JP2009506843A - Artificial disc - Google Patents

Abstract

An artificial disc, a system including such an artificial disc, and methods of use thereof are described. The artificial intervertebral disc includes upper and lower motion endplates separated by a compressible core member. The artificial disc exhibits stiffness in the vertical direction, torsional stiffness, bending stiffness in the sagittal plane, and bending stiffness in the anterior plane, and the degree of these features can adjust the composition, structure, and other features of the disc Can be adjusted independently. An artificial disc provided by an embodiment of the present invention is coupled directly or indirectly to a first endplate and a first endplate in a substantially parallel relationship with the first endplate. A fixed member that includes a second end plate and a core member disposed between the first and second end plates, and the first end plate is selectively movable from a non-deployed state to a deployed state. including.

Description

(Background of the Invention)
The intervertebral disc is anatomically and functionally complex. The intervertebral disc consists of three component structures. (1) nucleus pulposus, (2) annulus fibrosus, and (3) vertebral motion endplate. The biomedical composition and anatomical arrangement within these component structures are related to the biomechanical function of the disc.

  The spinal disc may be displaced or damaged due to trauma or disease processes. When misalignment or damage occurs, the nucleus pulposus may escape and protrude into the spinal canal or intervertebral foramen. Such a deformation is known as a herniated disc or a tight waist. An intervertebral hernia or tight waist may compress the spinal nerve that passes through the partially obstructive hole and exits the spinal canal, causing pain or paralysis in its distribution area.

  To alleviate this condition, it may be necessary to remove the diseased disc and fuse two adjacent vertebrae. In this procedure, spacers are inserted where they are initially occupied by the intervertebral disc, but additional fixation devices such as plates and rods may be added to increase stability. Despite the excellent short-term outcomes of such “spine fusion” for traumatic and degenerative spinal cord diseases, long-term studies reveal that changes in the biomechanical environment lead to degenerative changes in the mobile adjacent disc It has become. Adjacent intervertebral discs have increased motion and stress due to the increased stiffness of the fused portion. In the long term, this change in the dynamics of the spine exacerbates these adjacent discs.

  In order to avoid this problem, replacement of an artificial disc has been proposed as an alternative to spinal fusion. Various types of artificial intervertebral discs have been developed to restore the normal kinematics and load dispersibility of natural discs, but they are grouped into two categories: ball and socket discs and elastomeric discs can do.

  Ball joint-type artificial discs usually consist of metal plates, one connected to the upper vertebra and the other to the lower vertebra, with a polyethylene or metal seat as a sphere. The metal plate may have a concave region that accommodates the seating surface. The ball joint type allows free rotation or movement between the vertebrae to which the intervertebral discs are attached, and therefore has no load balancing capability for bending and translation (some ball joint type artificial discs have limited rotation properties). And the proper rotational force aimed at natural intervertebral discs has not yet been resolved). This type of artificial disc has a very high stiffness in the vertical direction and they cannot reproduce the normal compression stiffness of a natural disc. In addition, the lack of load bearing capacity in these types of intervertebral discs causes the adjacent discs to carry extra loads, resulting in eventual degeneration of the adjacent discs and facets. These types of intervertebral discs also cannot reproduce the rotational instantaneous access (IAR) that natural intervertebral discs have as a direct result of the lack of natural compressibility.

  In an elastomeric prosthetic disc, the elastic polymer is between the metal plates, which are fixed to the upper and lower vertebrae. The elastic polymer can be joined to the metal plate by making the contact surface of the metal plate rough and porous. This type of intervertebral disc can absorb impacts in the vertical direction and has a load bearing capability. However, this structure has problems with the contact surface between the elastic polymer and the metal plate. Even when the contact surface of the metal plate is treated for better bonding, polymer fragments are produced after prolonged use. Furthermore, the bonding of the elastomer to the metal substrate tends to fail after prolonged use due to insufficient shear fatigue strength.

  Due to the aforementioned disadvantages associated with ball joint and elastomeric discs, there has long been a need for new artificial devices. Some such artificial devices are described in US patent application Ser. No. 10 / 632,538, filed Aug. 1, 2003, and US Patent Application No. 10 / 903,276, filed Jul. 30, 2004. Each of which is incorporated herein by reference. The aforementioned application describes, inter alia, an artificial intervertebral disc that includes an upper end plate, a lower end plate, and a compressible core member positioned between two end plates. Several artificial disc embodiments are described, including monolithic, two-body, three-body, and four-body structures.

  Although such artificial discs and their methods of use are highly promising, there remains a need for improvements in artificial discs and their methods of use.

(Related literature)
Patent Literature 1, Patent Literature 2, Patent Literature 3, Patent Literature 4, Patent Literature 5, Patent Literature 6, Patent Literature 7, Patent Literature 8, Patent Literature 9, Patent Literature 10, Patent Literature 11, Patent Literature 12, Patent Literature 13, Patent Document 14, Patent Document 15, Patent Document 16. Further, Patent Literature 17, Patent Literature 18, Patent Literature 19, and Patent Literature 20 are disclosed. Further, see Non-Patent Document 1.
US Pat. No. 3,867,728 U.S. Pat. No. 4,911,718 US Pat. No. 5,039,549 US Pat. No. 5,171,281 US Pat. No. 5,221,431 US Pat. No. 5,221,432 US Pat. No. 5,370,697 US Pat. No. 5,545,229 US Pat. No. 5,674,296 US Pat. No. 6,162,252 US Pat. No. 6,264,695 US Pat. No. 6,533,818 US Pat. No. 6,582,466 US Pat. No. 6,582,468 US Pat. No. 6,626,943 US Pat. No. 6,645,248 US Patent Application Publication No. 2002/0107575 US Patent Application Publication No. 2003/0040800 US Patent Application Publication No. 2003/0045939 US Patent Application Publication No. 2003/0045940 Masahiki Takahata, Uasuo Shikinami, Akio Minami, "Bone Ingredient Fixation of Intelligent InterCondiction of Bio-Ceramic of SP. 637-44

  Prosthetic discs and methods of using such discs are provided. The artificial intervertebral disc typically includes an upper end plate, a lower end plate, and a compressible core member located between the two end plates.

  In some embodiments, the artificial intervertebral disc is characterized by including an upper end and a lower end motion endplate separated by a compressible element. The two plates are held by at least one fiber wound around at least one portion of the upper end plate and at least one portion of the lower end plate. The fibers are generally high tension fibers with high modulus and high wear resistance. The elastic properties of the fibers, as well as factors such as the number of fibers used, the thickness of the fibers, the number of fiber winding layers, the tension applied to each layer, and the crossing pattern of the fiber windings, The intervertebral disc structure allows the functional features and physical mechanics of a normally functioning natural intervertebral disc to be mimicked. Alternatively, the two plates are held by an engagement mechanism that connects each plate to the compressible element. The intervertebral disc may be used with a separate vertebral body fixation element or it may include an integrated vertebral body fixation element.

  A number of optional core materials and structures can be incorporated into each of the artificial disc embodiments described herein. For example, the core member may be formed from a suitable high-rigidity material such as polyurethane or silicone, and is usually manufactured by injection molding or compression molding. In another example, the core member may be formed from a layer of fabric woven from fibers. In yet another example, the core member may include a combination of materials such as fiber reinforced polyurethane or silicone. As a further option, one or more spring members may be coaxially connected (the core member has a generally cylindrical or toroidal shape and the spring is centered) between the upper and lower endplates with the core member. Can be arranged.

  In another embodiment, the core structure includes two or more core members having different load bearing capabilities and the ability to change the center of rotation of the core structure. The variability of the core member may be provided by selection of material, structure, or other characteristics. In yet another embodiment, the core structure includes one or more core members formed or constructed from materials that provide various stiffnesses or other material properties to accommodate different loads or load configurations. Examples of these core structures include cores having separate portions formed from different materials, cores having grooves or other features formed on a portion of the core member for other purposes (such as sterilization), And a core having a coil or coupler coupled to or integrally formed with the core member.

  In yet another embodiment, the core structure is provided with one or more mechanisms adapted to adjust the size, shape, arrangement, or other features or combination of features of the core member. For example, the core member may include threads, slots, and claws, or other mechanisms that provide the ability to adjust the height of the core or adjust other properties of the core.

  Some particularly preferred core structures include a hollow member adapted to expand after implantation of the artificial disc. In this way, the artificial disc is in a contracted state (the core is not inflated) for delivering and implanting the disc, and an expanded state (the core is inflated) adapted for use by the patient after implantation. Is provided). These core structures are provided with fluid ports that are adapted to promote expansion of the core. Alternatively, a fluid communication lumen extending from the hollow core member may be provided, and a lumen through which an inflation medium may be injected into the core is provided. The hollow core may be provided with two or more components, each of which may be independent or in fluid communication with each other.

  Some optional endplates and associated mechanisms may be incorporated into each of the artificial disc embodiments described herein. For example, the end plate may be curved or bean-shaped to facilitate rotation of the intervertebral disc within the intervertebral space. Alternatively, the end plate may be of a partially cylindrical shape that is adapted to engage or retain a substantially cylindrical core member.

  Other and further devices, apparatus, structures, and methods are described by reference to the following drawings and detailed description.

  The drawings included in this application are not necessarily drawn to scale, and some components and characteristics are exaggerated for clarity.

(Description of Preferred Embodiment)
Before disclosing the present invention, it is to be understood that the present invention is not limited to the specific embodiments described, and thus may, of course, vary. Since the scope of the present invention is limited only by the appended claims, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. Should be further understood.

  If a range is provided, unless it is clearly explained by context, the range up to at least one-tenth of the lower limit unit, between the upper and lower limits of the range, and any It is understood that other proposed values or values that lie within the proposed range are encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included in the smaller ranges and are further encompassed within the present invention, unless they are specifically excluded from the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.

  Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or similar to those described herein can also be used in the practice and testing of the present invention, the preferred methods and materials are described below. All publications mentioned in this application are herein incorporated by reference to disclose and describe methods and / or materials related to those cited in the publication.

  As used in this application and the appended claims, the singular forms “a”, “an”, and “the” are plural unless the context clearly dictates them. Must be noted.

  The publications mentioned in this application provide only disclosure prior to the filing date of the present application. Nothing in this application shall be construed as an admission that the present invention is not entitled to an invention prior to the date of those publications because of the prior invention. In addition, the stated publication date may differ from the actual publication date and may need to be individually confirmed.

  As will be apparent to those skilled in the art upon reading this disclosure, each individual embodiment described and illustrated herein has distinct components and features, and others without departing from the scope or spirit of the invention. Can be easily separated or combined with the features of any of the embodiments.

(I. Outline of the artificial disc to be described)
Disclosed herein are artificial discs, methods of using such discs, devices for implanting such discs, and methods for implanting such discs. It should be understood that the prosthetic discs, implantation devices, and methods are not limited to the specific embodiments described, and may, of course, vary. Since the scope of the present invention is limited only by the appended claims, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. It will be further understood.

  The artificial disc is preferably an artificial or artificial device that is constructed or shaped to be used in place of an intervertebral disc in a vertebrate organism, for example, the spine of a mammal such as a human. This artificial intervertebral disc has a size that can substantially occupy the space between two adjacent vertebral body portions, ie, the intervertebral disc gap, that appears when a naturally occurring intervertebral disc between two adjacent vertebral body portions is extracted. Substantial occupancy refers to occupying a sufficient volume in the space between two adjacent vertebral bodies that can perform some or all of the functions that a natural disc performs so that the artificial disc can serve as a replacement. . In certain embodiments, the prosthetic disc may have a generally bean-like structure similar to a naturally occurring interbody disc. In many embodiments, the length of the artificial disc ranges from about 5 mm to about 40 mm, preferably from about 10 mm to about 25 mm, and the width of the artificial disc ranges from about 2 mm to about 50 mm, preferably from about 10 mm to about 35 mm. The height of the disc ranges from about 2 mm to about 15 mm, preferably from about 5 mm to about 12 mm.

  The intervertebral disc typically includes both upper (or upper) and lower (or lower) end-of-motion or bone contact structures (eg, adjacent plates, severing plates, spikes, keels, porous surfaces and the like) The inferior endplates are separated from each other by a compressible element, and the connection structure of the endplates and the compressible element provides an artificial intervertebral disc that functionally closely imitates a real intervertebral disc. Some of the properties of the present intervertebral disc include that the upper and lower end motion endplates are held by, for example, at least one fiber of a fiber compressible element and wound around at least a portion of each of the upper and lower end motion endplates. It is that. Thus, in these embodiments, the two end plates (or substrates) are wound in at least one domain / part / region of the upper end plate and the lower end plate so that the plates are joined together. Held together by one or more fibers.

  A method of using the present artificial disc is also provided. The artificial disc finds use in replacing damaged or malfunctioning discs in vertebrate organisms. In general, a vertebrate organism is a “mammal” or “mammal” and these terms include carnivores (eg, dogs and cats), rodents (eg, mice, guinea pigs and rats), rabbits (eg, , Rabbits) and primates (eg, humans, chimpanzees and monkeys) are used broadly to describe life forms within the mammalian class. In many embodiments, the subject is a human.

  In general, the device is used by first removing part or all of a natural disc that is to be replaced from a subject or patient in accordance with a typical surgical procedure that creates a disc space. Next, the artificial disc is transplanted or placed in the gap between the discs, and the exchanging of the extracted disc and the artificial disc is completed. This implantation step may include a vertebral body fixation element implantation sub-step, a post-implantation vertebral body fixation step, or other variations, depending on the particular configuration of the prosthetic device used. Furthermore, the implantation step described above may include the use of one or more implantation devices (or disc delivery devices) to implant system components at the implantation site.

  Two different representative intervertebral discs are shown in FIGS. 1A and 1B. These intervertebral discs, and others, are also described in US patent application Ser. No. 10 / 632,538 (“the '538 application”) filed Aug. 1, 2003, and US filed Jul. 30, 2004. No. 10 / 903,276 (“the '276 application”) is described in further detail, each of which is incorporated herein by reference. Much of this review, including FIGS. 1A-1B, 2 and 3, is from a portion of the '276 application.

  As shown in FIGS. 1A and 1B, each of the artificial discs 10 includes an upper end plate 11 and a lower end plate 12. Upper and lower endplates 11 and 12 are substantially planar substrates, and these plates are typically about 5 mm to about 40 mm in length, such as about 10 mm to about 25 mm, and about 10 mm to about 35 mm in width, etc. About 2 mm to about 50 mm, and about 0.25 mm to about 6 mm in thickness, such as about 1 mm to about 4 mm. The top and bottom endplates or equivalents are made from a biocompatible material that also provides the necessary mechanical properties; typical materials from which the endplates may be made are known to those skilled in the art. Multi-phase alloys such as titanium, titanium alloy, stainless steel, cobalt / chromium / molybdenum alloy, MP-35N, etc .; polyethylene (UHMWPE) having an ultra-high molecular mass (molecular weight), polyether ether ketone (PEEK), etc. Including but not limited to plastic; ceramic; graphite and the like. As shown in FIGS. 1A and 1B, it is a compressible element 17 that separates the upper and lower endplates. The thickness of the compressible element may vary, but in many embodiments, includes from about 2 mm to about 10 mm and ranges from about 1 mm to about 15 mm.

  The intervertebral disc is a site extending to the outer periphery of the intervertebral disc, an annular site 13 (i.e., a ring) that is a domain or region, and a nuclear site (i.e., a site, domain or region that is centrally surrounded by the annulus) (Nucleus) 14 is further included.

  As shown in FIGS. 1A and 1B, in many embodiments the plate has multiple such sites, but the plate includes a single site that is wrapped around the fibers to hold the plate. As shown in FIGS. 1A and 1B, the motion endplates 11 and 12 include a plurality of slots 15 that may penetrate or be wound, for example, through the fibers of a fiber compressible element, as shown. In many embodiments, the number of different slots present on the periphery of the device ranges from about 4 to about 36, such as from about 5 to about 25. As shown in FIGS. 1A and 1B, at least one fiber 16 that forms part of the compressible element is held at the upper and lower ends by, for example, passing slots in the upper and lower plates to hold the plate. It is wound around the lower end plate.

  The compressible element 17 is usually composed of one or more fibers, which are generally strong fibers having high elastic modulus and high wear resistance. A strong fiber refers to a fiber that can resist a longitudinal stress of at least about 50 MPa, such as at least about 250 MPa, without breaking. Since fibers have a high modulus, their modulus is generally at least about 100 MPa, usually at least about 500 MPa. The fibers are generally elongated fibers having a diameter ranging from about 0.1 mm to about 5 mm, such as from about 0.2 mm to about 2 mm, and the length of each individual fiber making up the fiber component can be from about 0.3 m. It may range from about 0.1 m to about 20 m, such as about 3 m.

  The fibers making up the fibrous compressible element may be made from any suitable material, such as alloys, polyesters (eg Dacron), polyethylene, polyaramid, polytetrafluoroethylene, carbon fibers. Or including materials including polymers including glass fiber, polyethylene terephthalate, acrylic polymer, methacrylic polymer, polyurethane, polyurea, polyolefin, halogenated polyolefin, polysaccharide, vinyl polymer, polyphosphazene, polysiloxane, nylon and the like, It is not limited to them.

  A fiber compressible element comprised of one or more fibers wound around one or more sites on the top or bottom plate may constitute a variety of different forms. For example, the fibers may be wound into a pattern having an oblique arrangement to mimic an annulus of an intact disc, and a representative oblique fiber form or arrangement is shown in FIG. 1A. The number of wound fiber layers may vary to obtain mechanical properties similar to an intact disc. If desired, structural integrity may be relaxed by including a horizontal winding configuration, as shown in FIG. 1B.

  In certain embodiments, the fiber compressible element 20 has a fiber component 21 that is confined to an annular portion 22 of the intervertebral disc, for example, a portion along the outer periphery of the intervertebral disc. FIG. 2 provides a depiction of this embodiment, where the fiber component is limited only to the annulus of the intervertebral disc and includes both skewed and horizontal turns. A separate polymer component 23 present in the core is further shown. The fiber turns of the various layers of fibers may be at different angles from each other, and the particular angle of each layer may be selected to provide a configuration that most effectively mimics the natural disc. Furthermore, the tension applied to the fibers of each layer may be the same or different.

  In yet other embodiments, the fiber component of the fiber compressible element may extend beyond at least about all but not all of the annular portion of the intervertebral disc.

  In certain embodiments, the fiber compressible element further comprises one or more polymer components. When present, the polymer component can be made from a variety of different physiologically acceptable materials. Such representative materials include polydimethylsiloxane, polycarbonate polyurethane, aromatic polyurethane and aliphatic polyurethane, poly (ethylene propylene) copolymer, polyvinyl chloride, poly (tetrafluoroethylene) and copolymer, hydrogel and the like Including, but not limited to, elastomeric materials.

  The polymer component may extend over the entire site of a fiber compressible element that is confined to a particular domain, such as the circular and / or nuclear domain, or disposed between two endplates. Thus, in certain embodiments, the polymer component is limited to the nucleus region of the intervertebral disc, as shown in FIG. In FIG. 2, the fiber compressible element 20 includes a separate fiber component 21 located in the annular portion 22 of the disc, while the polymer component 23 is located in the nucleus portion of the disc. In other embodiments, the polymer component is located at both the cyclic and nuclear sites. In still other embodiments, the polymer component may be located only at the cyclic site.

  Depending on the desired morphology and mechanical properties, the polymer component may be integrated with the fiber component such that at least some of the fibers of the fiber component are incorporated into (eg, complexed with) at least a portion of the polymer component. Good. In other words, at least a portion of the fiber component is filled with at least a portion of the polymer component. For example, a two-dimensional stack of fiber components may be present inside the polymer component so as to fill the fiber component with the polymer component.

  In those forms where the fiber component and the polymer component are present in a composite form, the fibers of the fiber component may be treated to provide improved binding with the polymer component. Such representative fiber treatments include, but are not limited to, corona discharge, O2 plasma treatment, oxidation with strong acids (HNO3, H2SO4). In addition, a surface binder may be used and / or a monomer mixture of polymers may be polymerized in the presence of surface modified fibers to form a synthetic fiber / polymer structure. The fibers may also be a composite structure with an outer layer made of a material optimized for surface bonding. The composite structure may also consist of an outer jacket that provides bonding to the polymer component but allows relative movement of the fiber component within the jacket.

  As noted above, the device may include one or more different polymer components. In these embodiments, if two or more different polymer components are present, any two given polymer components are different if they differ from each other with respect to at least one aspect, eg, composition, crosslink density, and the like. Considered different. Thus, two or more different polymer components may be made from the same polymer molecule, but may differ from each other with respect to one or more crosslink densities, fillers, and the like. For example, the same polymeric material may be present in both the disc annulus and the nucleus, but the cross-link density of the cyclic polymer component may be higher than the nucleus site. In still other embodiments, different polymer materials may be used for the polymer molecules that make up the polymer material.

  Forming intervertebral discs with desired functional characteristics that mimic naturally occurring functional characteristics, for example, by selecting specific fibrous and polymeric component materials and, for example, forms from the different representative types described above May be.

Such representative specific combinations include, but are not limited to:
1. 1. Biocompatible polyurethane, such as Ethicon Biomer, or Spectra polyethylene fiber, or Kevlar polyaramid fiber, or carbon fiber, reinforced with Dacron poly (ethylene terephthalate) fiber. 2. Biocompatible polysiloxane modified styrene ethylene butylene block copolymer sold under the trademark C-Flex reinforced with Dacron poly (ethylene terephthalate) fiber, or Spectra polyethylene fiber, or Kevlar polyaramid fiber, or carbon fiber. Biocompatible Silastic silicone rubber, or Spectra polyethylene fiber, or Kevlar polyaramid fiber, or carbon fiber, reinforced with Dacron poly (ethylene terephthalate) fiber.

  When using this intervertebral disc, the artificial disc is fixed to the vertebral body to which it is implanted. More specifically, the upper and lower plates of the intervertebral disc are secured to the adjacent vertebral body. Thus, the intervertebral disc is used with a vertebral body fixation element when in use. In certain embodiments, the vertebral body fixation element is integral to the disc structure, while in other embodiments, the vertebral body fixation element is separated from the disc structure.

  Another representative artificial disc 100 is shown in FIG. 3, which is also described in more detail in the '276 application. The artificial intervertebral disc 100 has an integrated structure including an upper motion end plate 110, a lower motion end plate 120, and a core member 130 held between the upper motion end plate 110 and the lower motion end plate 120. One or more fibers 140 are wound on the upper and lower motion endplates to join the motion endplates together. The winding of the fiber 140 allows constant axial rotation, bending, bending and extension between the endplates by the endplate. The core member 130 may be provided in an uncompressed or pre-compressed state. An annular capsule 150 is optionally provided in the space between the upper and lower motion endplates surrounding the core member 130 and the fibers 140. Upper end plate 110 and lower end plate 120 are generally flat planar members and are made from a biocompatible material that provides sufficient rigidity. Examples of materials suitable for use in the fabrication of the upper end plate 110 and the lower end plate 120 are titanium, titanium alloys, stainless steel, cobalt / chrome / manufactured by machining, forging, casting, metal injection molding. Molybdenum alloys and the like; plastics such as polyethylene (UHMWPE) and polyetheretherketone (PEEK) having ultra high molecular weight (molecular weight) manufactured by injection molding or compression molding; ceramics; graphite and the like. Optionally, the motion endplate may be coated with hydroxyapatite, titanium plasma spray, or other coatings to enhance bone ingrowth.

  As noted above, the upper and lower endplates are typically about 5 mm to about 40 mm in length, preferably about 10 mm to about 25 mm, about 2 mm to about 50 mm in width, preferably about 10 mm to about 35 mm, and have a thickness of About 0.25 mm to about 6 mm, preferably about 1 mm to about 4 mm. The size of the upper and lower movement endplates is selected primarily based on the size of the gap between adjacent vertebral bodies occupied by the artificial disc. Therefore, the length and width of the end plate in the range other than the above are possible but not typical. The upper surface of the upper motion end plate 110 and the lower surface of the lower motion end plate 120 are each preferably provided with a mechanism for fixing the motion end plate to the opposing surfaces of the upper and lower vertebral body parts into which the artificial intervertebral disc is transplanted. For example, in FIG. 3, the upper motion end plate 110 includes a plurality of fixed fins 111 a to 111 b. The fixing fins 111a to 111b are formed on the surfaces of the upper and lower vertebral body parts, and are intended to engage with the fitting grooves for fixing the movement end plates to the respective vertebral body parts. The fixed fins 11la to 11lb extend substantially perpendicularly from the outer surface of the generally planar surface of the upper motion end plate 110, that is, as shown in FIG. In the embodiment of FIG. 3, only two are shown in the cross-sectional view, but the upper motion end plate 110 includes three fixed fins 11la to 11lc. The first fixed fin 111 a is disposed in the vicinity of the outer end of the outer surface of the upper motion end plate, and has a length approximating the width of the upper motion end plate 110. The second fixed fin 111b is disposed at the center of the outer surface of the upper motion end plate and has a relatively short length substantially less than the width of the upper motion end plate 110. Each of the fixed fins 111a to 111b has a plurality of serrated shapes 112 positioned at the uppermost end of the fixed fin. The serrated 112 is intended to improve the ability of the fixation fins to engage the upper vertebral endplate 110 to the spine by engaging the vertebral body.

  Similarly, the lower surface of the lower movement end plate 120 includes a plurality of fixed fins 121a to 121b. The fixing fins 121a to 121b on the lower surface of the lower movement end plate 120 are structurally and functionally identical to the fixing fins 111a to 111b on the upper surface of the upper movement end plate 110 except for the position of the artificial intervertebral disc. The upper and lower fixed fins are not necessarily the same or similar and may differ from each other in terms of arrangement, size or position. Such differences are used to accommodate anatomical differences between the upper and lower vertebral body parts. The fixing fins 111a to 111b on the upper motion end plate 110 are intended to engage with the fitting grooves in the upper vertebral body, whereas the fixing fins 121a to 121b on the lower motion end plate 120 are used. It is intended to engage with a fitting groove formed in the lower vertebral body. Therefore, the artificial disc 100 is held at an appropriate position between adjacent vertebral body parts.

  The fixed fins 111, 121 may optionally include one or more holes or slots 115, 125. The holes or slots help to promote bone ingrowth that supports the fixation of the artificial disc 100 to the vertebral body.

  Upper motion end plate 110 includes a plurality of slots 114 that may penetrate or wrap fibers 140 as shown. The actual number of slots 114 included in the end plate is variable. Increasing the number of slots increases the circumferential density of the fibers connecting the endplates. Further, the shape of the slot may be selected to provide a variable width according to the length of the slot. For example, the width of the slot may taper from a relatively wide inner end to a relatively narrow outer end, or vice versa. Further, the fibers may be wound more than once in the same slot to increase the radial density of the fibers. In any case, this further approximates the stiffness of the natural disc by improving wear resistance and enhancing the torsional and bending stiffness of the artificial disc. Further, the fibers 140 may be pierced or wound into their respective slots, or selected slots as needed.

  As described above, the purpose of the fiber 140 is to retain the upper endplate 110 and the lower endplate 120, limiting the range of motion to mimic the natural disc range of motion and torsional and bending resistance. That is. Accordingly, the fibers preferably comprise strong fibers having a high modulus of elasticity, for example at least about 100 MPa, preferably at least about 500 Mpa. Strong fibers refer to fibers that can resist longitudinal stress of at least 50 Mpa, preferably at least 250 Mpa, without breaking. The fibers 140 are generally elongated fibers having a diameter ranging from about 100 μm to about 1000 μm, preferably from about 200 μm to about 500 μm. Optionally, the fibers may be treated with an elastomer to encapsulate the fibers (eg, injection molding or extrusion) to provide protection from tissue ingrowth and enhance torsional and bending stiffness, or The fibers may be coated with one or more other materials to enhance the stiffness and wear of the fibers. In addition, wetting agents such as saline may be injected into the core to moisten the fibers and promote the mimicking of the viscoelastic properties of natural discs.

  The fibers 140 may be made from any suitable material. Examples of suitable materials are polyester (eg Dacron®), polyethylene, polyaramid, polyparaphenylene terephthalamide (eg Kevlar®), carbon or glass fiber, polyethylene terephthalate, acrylic polymer, methacrylic Includes polymers, polyurethanes, polyureas, polyolefins, halogenated polyolefins, polysaccharides, vinyl polymers, polyphosphazenes, polysiloxanes and the like.

  The fibers 140 may be terminated on the motion endplate by knotting the fibers on the top surface of the motion endplate. Alternatively, the fiber 140 is terminated on the end plate by sliding the end end of the fiber into a slot on the end of the end plate, similar to the manner in which the yarn is held in the spool. May be. The slot may hold the fibers with pleats in the slot structure itself or with additional retainers such as ferrules. As a further alternative, pleats, such as claws, may be machined or welded to the end-of-motion structure to secure the distal end of the fiber. The fibers may then be occluded and fixed inside the folds. As yet a further alternative, the polymer may be used to secure the fibers to the endplate by welding. The polymer will preferably be composed of the same material as the fibers (eg, PE, PET, or other materials described above). Further, the fibers may be retained on the endplate by crimping the cross member that creates the T-joint to the fiber, or by crimping the sphere to the fiber to create a ball joint.

  The core member 130 is intended to provide support to the relative distance between the upper motion end plate 110 and the lower motion end plate 120 and to maintain the relative distance. The core member 130 is made of a relatively soft material, such as polyurethane or silicone, and is usually manufactured by injection molding. A preferred structure for the core member includes a core in the form of a hydrogel and an elastomer reinforced annulus. For example, the core, core portion 130 includes a hydrogel material such as water-absorbing polyurethane, polyvinyl alcohol (PVA), polyethylene oxide (PEO), polyvinyl pyrrolidone (PVP), polyacrylamide, silicone, or PEO-based polyurethane. But you can. The ring may be an elastomer such as silicone, polyethylene (eg, ultra high molecular weight polyethylene, UHMWPE), fiber reinforced polyurethane or polyester (eg, Hytrel®), polyethylene terephthalate, or polyparaphenylene terephthalamide (eg, Kevlar®) may be included.

  The shape of the core member 130 (as well as the material constituting the core member and the size of the core member) may vary to obtain the desired physical or performance properties, but the shape is typically It is generally cylindrical or bean-shaped. For example, the shape, size and material of the core member 130 directly affects the bending, extension, lateral bending, and axial rotation of the artificial disc.

  The annular capsule 150 is preferably composed of polyurethane or silicone and may be made by injection molding, two-point component mixing, or dipping the endplate-core-fiber assembly into the polymer solution. The function of the annular capsule is to hold the disc material (eg, fiber tufts) within the body of the disc and serve as a barrier to maintain natural ingrowth outside the disc.

(II. Core structure)
Some alternative core structures are described below. These core structures are preferably incorporated into one or more artificial discs constructed as described above, or may be adapted for use or use with other known artificial discs.

  Referring to FIGS. 4A-4C, a first alternative core structure is shown. The core structure includes a substantially cylindrical core member 150 that is configured to be positioned between a set of endplates 110 and 120 on an artificial disc. As shown in FIG. 4C, the motion end plates 110, 120 have the same size and shape as those described elsewhere in the present application, and are made of the same material. The core member 150 is a solid, cylindrical structure having a length and width adapted to substantially occupy the internal volume of the artificial disc between the upper and lower endplates. The core 150 is composed of hydrogel, polyurethane, polyvinyl alcohol (PVA), polyethylene oxide (PEO), polyvinyl pyrrolidone (PVP), polyacrylamide, silicone, PEO-based polyurethane, silicone and other elastomers, polyethylene (for example, ultra high molecular weight polyethylene, UHMWPE) and the like, including fiber reinforced polyurethane or polyester (eg, Hytrel®), polyethylene terephthalate, or polyparaphenylene terephthalamide (eg, Kevlar®), and any one or more of the above Materials may be included.

  In some preferred embodiments, the core member 150 includes, for example, an inner core member 152 and an outer core member 154 shown in FIG. 4B. The inner core member 152 and the outer core member 154 may be composed of a single material, may be composed of different materials, or may be composed of the same material having different material properties. When using different materials or different material properties, the performance of the core 150 may vary to achieve the desired result. For example, a relatively soft material (ie, low durometer hardness) is used to construct the outer core member 154 while a relatively hard material (ie, high durometer hardness) is used for the inner core member 152. You may use for the composition of. As such, the inner core member 152 is adapted to provide a primary source of support for the core member 150 and the outer core member 154 provides consistency for a composite core structure.

  Due to the substantially cylindrical shape of the core member 150, each endplate 110, 120 engages the core member 150 beyond a limited contact area along the upper and lower surfaces of the core member. The compressive load applied to each of the movement end plates is applied perpendicular to the longitudinal axis of the cylindrical core member. Furthermore, as the load on the upper 110 and lower 120 endplates increases, the contact area that receives the load expands due to the planarization of the generally cylindrical core member 150. This flattening of the core member helps maintain the integrity of the core and performance under relatively strong compressive loads, and provides progressively greater resistance to the compressive forces of the two end plates.

  The cylindrical shape of the core member 150 is also longer than the amount of rotation allowed by an ordinary, relatively small core having a more conventional shape, as shown, for example, by the arrow “R” in FIG. 4C. Allows a relatively large amount of rotation of the upper and lower endplates that surround the shaft. This rotation of the motion endplates 110, 120 surrounding the longitudinal axis of the core member 150 is intended to mimic the rotation obtained by the natural disc or to produce other desired results. The artificial disc 100 is preferably placed in the space between the upper and lower vertebral bodies so that rotation around the longitudinal axis of the core member can be utilized for the desired outcome.

  As described elsewhere herein, the upper and lower motion endplates 110, 120 are each connected directly to the core member 150, or the motion endplates are fibers woven through the motion endplates, or They are connected to each other by fibers connected to the end plate. Additional mechanisms for connecting the intervertebral disc components can be utilized as well, and this mechanism can be understood by those skilled in the art. Furthermore, any annular capsule may be coupled to the artificial disc in the manner described above.

  Referring to FIGS. 5A and 5B, another alternative core structure is shown. The core structure includes a plurality of core members 160 having different performance properties that provide various load bearing and ability to change the center of rotation of the core structure. For example, FIG. 5A shows a core structure having two core members 160a and 160b. The front core member 160a is formed of one or more materials or configured to provide a relatively rigid core member. The rear core member 160b is formed of one or more materials or configured to provide a relatively rigid core member. Thus, the relatively rigid rear core member 160b is relatively soft and supports a greater load than the flexible front core member 160a, and the front core member 160a is positioned away from the rotating shaft. So it has a relatively large movement. Furthermore, by changing the rigidity of each of the front core member 160a and the rear core member 160b, the rotational axis of the core structure can be moved, thereby providing different ranges of motion for the front and rear core members.

  Another example is shown in FIG. 5B. The relatively high-rigidity center core member 160a is located between the first relatively soft peripheral core member 160b and the second relatively soft peripheral core member 160a. While the relatively rigid core member is located near the center of the core structure, resulting in a portion that receives the main axial load of the core structure, this configuration is relatively soft to be positioned around the core structure and more A movable core member is provided and the movable range of the core structure is expanded.

  Other variations of the structure shown in FIGS. 5A and 5B are also possible. Additional core members may be provided, for example, 4, 5, or 6 or more separate core members. Each of the core members may have a cylindrical cross-sectional shape, such as the core member shown in FIGS. 5A-5B, or they may have different cross-sections, such as elliptical, kidney-shaped, rectangular or geometric or irregular. It may consist of shapes. Each of the core members may be formed or constructed from a material that is relatively stiff, relatively soft and flexible, or has some other desired physical properties. The individual core members are then placed at the desired position between the two end plates of the core structure, for example by changing the degree of load experienced by the range of motion or by each separate core member. You may gain an effect.

  Furthermore, when the core structure is formed using fiber winding as described above, the position of the fiber winding is the position of a separate core member located between the upper motion end plate and the lower motion end plate. Adapted to work with. For example, in one embodiment, the fiber turn is located only around the endplate itself. In an alternative embodiment, the turns are located around each individual core member. In still other embodiments, the fiber turns are formed in a continuous meander pattern or one or more figure eight patterns, each surrounding each core member. Other variations of the winding pattern may be implemented to obtain the desired physical properties of the core structure.

  With reference to FIGS. 6A-6T, several further alternative core structures are shown. Exemplary core members are formed or constructed from materials that provide various stiffnesses or other material properties to accommodate different loads or load configurations. As shown in FIG. 6A, the first example, the generally cylindrical core member 170 includes a rear surface 172 and a front surface 174. In the preferred embodiment, the front surface 174 is less rigid than the rear surface 172. The difference in stiffness may be gradual, such as forming a stiffness gradient from the front surface 174 to the rear surface 172 through the core member 170. Alternatively, the difference in stiffness may be apparent from the portion of the core member that includes the rear surface 172, such as by forming a portion of the core member 170 that includes the front surface 174 of a different material, or in a different manner. Other variations and methods are also contemplated to obtain stiffness differences or other material properties between the front surface 174 and the rear surface 172 of the core member 170.

  Other example core members are shown in FIGS. 6B to 6D. Each of these example core members is generally cylindrical. Referring to the core member shown in FIG. 6B, the core member 180 includes an upper portion 182 and a lower portion 184 that are located on either side of the intermediate portion 186. Upper portion 182 and lower portion 184 are preferably formed from a relatively rigid polymeric material or other material having a relatively high stiffness. The intermediate portion 186 is preferably formed from a relatively soft material having a relatively low stiffness. This structure provides a core structure 180 that has a relatively large degree of torsional motion compared to an equivalent core that does not have a relatively soft intermediate portion. Similarly, the core member 188 shown in FIG. 6C is an integrated structure formed from a polymer or other material and has a plurality of grooves 190 formed around the core member. Each groove has a depth and width selected to obtain desired performance characteristics, such as torsional resistance and increased or decreased load bearing capacity. Finally, the core member 192 shown in FIG. 6D has a composite structure including a plurality of sections 194a to 194n. The composite structure is formed such that each section is formed or constructed from a material having the desired physical properties, and the entire core member 192 possesses the desired combination of such physical properties and achieves the desired performance. The For example, the core member 192 may be formed by alternately arranging high-rigid sections and flexible and soft sections. Although the figure shows four such sections 194a-194d, the core member may comprise more or less sections to achieve the desired result.

  Other examples of the core member are shown in FIGS. 6E to 6G. The core member 196 includes a generally cylindrical central portion 197 that is typically formed from a polymeric material or other suitable core member material. The coil member 198 is disposed around the central portion 197. Coil member 198 may be in the form of a compression spring or other suitable member. In the illustrated embodiment, the coil member 198 provides a restraint that substantially prevents central radial expansion that occurs as it is loaded. For example, FIG. 6F shows a core member 196 in an unloaded and uncompressed state, and the coil member 198 is not compressed and extends around the center. As the load “L” is applied, the central portion 197 and the coil member 198 are compressed as shown in FIG. 6G. The coil member 196 prevents radial expansion or expansion of the central portion 197 of the core member. In an alternative embodiment, not shown, the coil member is replaced with a thin outer layer that is shaped to allow corrugation, or loading and unloading of the core, while substantially preventing radial expansion of the center of the core. May be.

  Another example of the core member is shown in FIG. 6H. The generally cylindrical core member 200 includes an upper portion 202 and a lower portion 204 with a coupling portion 206 located between the upper portion 202 and the lower portion 204. Each of the upper portion 202 and the lower portion 204 is preferably formed from a polymeric material or other suitable material having a relatively high stiffness. The coupling portion 206 is preferably formed from a sufficiently soft and flexible material that allows axial compression and a relatively high degree of rotational freedom.

  Further examples of the core member are illustrated in FIGS. 6I to 6K. These example core members include a mechanism that is adapted to extend the height of the core member. In some preferred embodiments, the height of the core member can be adjusted to its original position, for example, after deployment of the core member between two vertebral bodies. Referring initially to FIG. 6I, the core member 208 includes an upper end 210 and a separate lower end 216. The upper end includes an uppermost end 212 and a generally cylindrical upper side wall 214. The lower end 216 includes a lowermost end 218 and a generally cylindrical lower side wall 220. The interior of the upper sidewall 222 and the exterior of the lower sidewall 224 each include a mating member, such as a mating thread, a V-shaped notch, a claw, or other similar mechanism. The fitting members of the upper end portion 210 and the lower end portion 216 are adapted to selectively connect the upper end portion to the lower end portion and to adjust the connection position so that the height of the core member 208 can be adjusted. . For example, when screw threads are fitted, the height of the core member 208 is adjusted by rotating the upper end 210 with respect to the lower end 216 and loosening the upper end screw or with respect to the lower end. The upper end may be raised. When fitting V-shaped notches and claws, the upper end 210 may be raised or lowered with respect to the lower end 216, and the core member may be installed at a desired overall height.

  An example of the core member 208 having the upper end portion 210 and the lower end portion 216 connected by the fitting member is shown in FIG. 6J. The fitting member includes a set of claws 230 formed on the outer periphery of the lower side wall and a V-shaped cut 232 formed on the inner periphery of the upper side wall. In this embodiment, the upper end 210 may be installed at a first position with respect to the lower end 216, and the V-shaped cut 232 at the upper end engages with the lower claw 230 at the lower end. The first position corresponds to a relatively low overall height of the core member 208. Alternatively, the upper end 210 may be installed at a second position with respect to the lower end 216, and the V-shaped cut 232 at the upper end engages with the upper claw 230 at the lower end. The second position corresponds to a relatively high overall height of the core member.

  Another example of the core member 208 having an upper end portion and a lower end portion connected by the fitting member is shown in FIG. 6K. The fitting member includes fitting threads 236 formed on the outer periphery of the lower side wall 220 and the inner periphery of the upper side wall 214. In this embodiment, the upper end 210 is rotated relative to the lower end 216 (or the lower end is rotated relative to the upper end), and the upper end is raised or lowered relative to the lower end, thereby causing the core member 208 to move. Adjust the overall height.

  6L-6N illustrate a method of forming the composite core member 208. FIG. In the first step shown in FIG. 6L, the central portion 240 of the core member 208 is formed from a relatively rigid material, such as a polymer material or other suitable material. The center may be formed by extrusion, casting, or any other suitable method known to those skilled in the art. The braid 242 is then affixed or attached to the central portion 240, for example, as shown in FIG. 6M. The braid 242 is preferably formed from a material having the property of providing a desired amount of torsional resistance of the core member 208 to obtain the desired performance characteristics for the core structure. Preferred materials for use as the braid are polyesters, polyethylenes, or polymers such as Kevlar. Other materials that may be used include metals such as stainless steel or a suitable metal alloy. When the braid is pasted, the outer layer 244 is pasted so as to cover the entire braid 242 and the central portion 240, and the core member 208 is completed. The outer layer 244 is made of a relatively soft and flexible material, and preferably strengthens bending, bending and extending of the core member.

  6P-6T illustrate several core structures and methods that are adapted to promote sterilization of the core. Referring initially to FIGS. 6P, 6Q, and 6R, a core member 208 is shown having a plurality of ridges 250 formed on an upper surface (upper) and a lower surface (lower). As illustrated, the core member 208 is generally cylindrical, although other core member shapes and sizes are also contemplated. For example, the core member 208 may have a structure or be formed from a material in a method according to any of the other embodiments described herein. The ridges 250 formed on the top and bottom surfaces include a first plurality of raised, semi-circular portions that form a generally radial pattern 252, each of the first plurality of raised, semi-circular portions being the center of the surface. Extends radially from nearby locations to the outer edge. The ridge 250 includes a second plurality of raised, semi-circular portions 254 forming a generally circular pattern, each of the second plurality of raised, semi-circular portions having a generally circular pattern in the edge of the surface of the core member. Extend to the vicinity. Accordingly, the generally radial pattern 252 formed by the first plurality of raised semicircular members traverses the generally circular pattern 254 formed by the second plurality of raised semicircular portions.

  The purpose of the ridge 250 formed on the upper and lower surfaces of the core member is to separate the main part of the core member 208 from the upper end plate and the lower end plate. This provides a relatively small volume of unoccupied space between the core member 208 and the upper and lower endplates. The unoccupied space improves the effectiveness of the sterilization treatment by facilitating the passage of the sterilizing agent between the core member and the respective endplates.

  As noted, the collar 250 illustrated in the embodiment shown in FIGS. 6P-6R is generally in the shape of a raised, semi-circular portion that extends outwardly from the top and bottom surfaces of the core. Each raised, semi-circular portion is generally elongated and extends in a generally radial pattern or a generally circular pattern. Other patterns and other shapes for the heel are also contemplated. For example, the ridge may be formed by a plurality of generally aligned, raised portions, by a plurality of concentric circular raised portions, or by any other geometric or non-geometric pattern.

  Another core member embodiment is shown in FIG. 6S. There, the core member 208 includes a plurality of raised ridges 260 formed on the top and bottom surfaces (the bottom surface is not shown in FIG. 6S). The raised aneurysm 260 also functions by separating the major portion of the core member 208 from the upper and lower motion endplates, so that a relatively small non-contact between the core member and the respective motion endplates. Provides space for occupied volume. As described above, this unoccupied volume space promotes sterilization by improving the ability of the sterilant to pass between the core member and the respective endplate.

  Yet another core embodiment is shown in FIG. 6T. In this embodiment, the core member 208 includes an integrated mesh 270 formed from polyethylene terephthalate (PET). The integrated mesh 270 includes a plurality of non-geometric raised portions that function to create an unoccupied space between the main portion of the core member and the respective upper and lower motion endplates. As described above, this unoccupied volume space promotes the sterilization of the resulting artificial disc by improving the ability of the sterilant to pass between the core member 208 and the respective endplate.

  With reference to FIGS. 7-10, several embodiments of adjustable core structures are shown. In these preferred embodiments, the core structure is configured such that it may be adjusted to its original position, for example after deployment between a set of vertebral bodies. In FIG. 7, the artificial disc 280 is implanted between a set of adjacent vertebral bodies 296,298. The artificial intervertebral disc 280 includes an upper motion end plate 282, a lower motion end plate 284, and a core member 286 located between the upper motion end plate and the lower motion end plate. Upper end plate 282 and lower end plate 284 are preferably secured to the respective vertebral body in the manner described above with respect to other exemplary intervertebral disc structures described herein. The core member 286 comprises a hollow member adapted to adjust the effective volume of the core member 286 by receiving an expansion medium via the expansion port 288. The amount of expansion medium contained within the hollow member determines the physical properties of the core member 286. For example, if the hollow portion of the core member 286 is filled with an inflation medium, the core member 286 will be relatively stiff and have a maximum or near maximum volume. As the amount of expansion medium in the hollow portion of the core member decreases, the core member 286 gradually softens and becomes more flexible and the volume decreases. In this way, the user can adjust the physical properties and size of the core member by adjusting the amount of expansion medium contained in the hollow portion of the core.

  The core member 286 may be provided in any size or shape necessary to achieve the desired clinical result. For example, the core member may occupy the entire space between the upper end plate 282 and the lower end plate 284, or may occupy only a portion of the space and have one or more other different structures. The core member portion may constitute the remainder. The core member 286 may be generally cylindrical, kidney-shaped, or other geometric shape or irregular shape suitable for a particular application.

  FIG. 7 illustrates a method for adjusting the volume of the core member 286. Needle 290 is inserted into the spinal cord site to allow access to the hollow portion of the core member. Needle 290 passes through inflation port 288 and is inserted into the hollow portion of the core member. The inflation medium is then added or pulled through the inflation needle 290 to the hollow portion. Preferably, a radiopaque marker 292 or other similar indicator is secured to the core member 286 at the location of the inflation port 288 to facilitate detection of the inflation port by fluoroscopy.

  FIG. 8 illustrates an alternative structure for a core member that includes a fluid communication lumen 294. The fluid communication lumen 294 comprises an extended tubular member that defines an internal lumen that connects the interior of the hollow portion of the core member to a port 296 located at the proximal end of the fluid communication lumen. The fluid communication lumen 294 extends from the rear portion of the core member 286 to the outside. Preferably, when implanting the artificial disc 280, the fluid communication lumen 294 is positioned so that access to the port 296 is gained at the proximal end of the channel without the need to gain access to the interior of the spinal column. For example, the proximal end of the fluid communication lumen 294 may be located directly below the patient's skin surface at a location that provides immediate access for adjustment of the core member 286. Thus, the port 296 may be accessed by an inflation medium that is infused or removed from the hollow member of the core member through the fluid communication lumen 294 directly under the skin surface and other members.

  In any of the embodiments shown in FIGS. 7 and 8, the artificial disc 280 may be implanted while the core member 286 is in an unexpanded state, corresponding to the thinnest state. This provides the ability to implant the prosthetic disc 280 through a relatively small implantation window that would be necessary if the prosthetic disc was deployed in a fully expanded state. Alternatively, if the prosthetic disc 280 is deployed in a disassembled state, the core member 286 is still implantable in its thinnest state and then expanded in its original position after deployment. In any event, the ability to deliver the core member 286 in an unexpanded condition allows the surgeon to implant the device through a relatively small implantation window.

  Preferably, the inflation medium comprises saline or other incompressible inert liquid. Other materials may be used to obtain the desired result. The inflation medium may be applied to or removed from the core member 286 at any time after surgery to adjust the performance of the artificial disc 280. The hollow portion of the core member may comprise a plurality of independent or interdependent chambers, each adjustable to change the height, size or physical properties of one or more portions of the core member It is also contemplated that it may be. For example, a four chamber system provides the ability to adjust the placement of the core member to regulate scoliosis, kyphosis, and kyphosis.

  Examples of multiple chambers are shown in FIGS. 9A-9B. The core member 302 is located between the upper end plate 304 and the lower end plate 306 and interconnects the first fluid chamber 308, the second fluid chamber 310, and the first and second fluid chambers. Fluid communication channel 312. The core member 302 also optionally includes an inflation port and (and optionally) a fluid inflation lumen to provide a mechanism for inflation or deflation in situ as described above with respect to FIGS. The two fluid chambers 308, 310 provide the necessary compression stiffness for the core member of the artificial disc 300. The two fluid chambers 308, 310 are formed in any desired shape suitable to provide the desired physical performance, such as a generally cylindrical shape, kidney-shaped cross section, or other geometric shape or irregularity. The

  FIG. 9A illustrates the core member 302 with the first fluid chamber 308 and the second fluid chamber 310 each having approximately the same size and shape. An inflation fluid, such as saline, occupies the respective interior space of the fluid chamber and can flow from the first fluid chamber 308 to the second fluid chamber 310 via the fluid communication channel 312. FIG. 9B illustrates the core member in a bent state. Due to the bending load of the upper and lower endplates 304, 306, fluid passes from the first fluid chamber 308 to the second fluid chamber 310. One or more fluid chambers provide physiological rigidity in compression by providing the ability to expand to accommodate the flow rate required to provide the range of motion, while the core member provides this range of motion. Enable.

  Although the embodiment illustrated in FIGS. 9A-9B shows two fluid chambers, other embodiments including three or more fluid chambers are also contemplated. For example, a single core member having three or more separate fluid chambers may be provided. In such cases, fluid communication channels may be provided between each of the fluid chambers, or only in selected chambers. Further, separate core members may be provided, and the flow rate between the separate core members may be provided by a fluid communication member that connects two or more separate core members.

  FIG. 10 shows an artificial disc 320 having a fluid communication channel 322 that connects to an interspinous stabilization device 324. The artificial intervertebral disc 320 preferably consists of a structure that is the same or similar to one of these described above with respect to FIGS. 7, 8, and 9A-9B, and is a superior motion endplate coupled to the superior vertebral body, A lower movement endplate coupled to the lower vertebral body, and a core member positioned between the two movement endplates. The core member includes at least one fluid chamber. The interspinous stabilization device 324 extends between an upper fixation member 326 coupled to the upper transverse process 332, a lower fixation member 328 coupled to the lower transverse process 334, and each of the upper and lower fixation members 326 and 328. , Including a fluid chamber 330 coupled between each. The fluid chamber 330 functions by providing resistance to compression, flexion, and rotation of the vertebral body to which the interspinous stabilization device 324 is coupled.

  The fluid communication channel 322 provides a flow rate between the core member of the artificial disc 320 and the fluid chamber 330 of the interspinous stabilization device 324. Thus, as the spine flexes or extends, fluid flows between the artificial disc 320 and the interspinous stabilization device 324, thereby increasing the volume of one of the components and decreasing the volume of the other. Depending on the relative size of the fluid chamber of the interspinous stabilization device and the fluid chamber of the intervertebral disc core member, the motion and range of motion of the spine are adjusted.

  It will be appreciated that the core member of the prosthetic disc 320 may optionally include one or more of the properties described above with respect to the core shown in FIGS. 7, 8 and 9A-9B. For example, the size (eg, height, volume) of the core member may be adjusted by providing an inflation port and a fluid communication lumen that provides fluid communication between the user and the core member. Other combinations of properties are also contemplated, as will be appreciated by those skilled in the art.

(III. End plate and related mechanisms)
Some alternative end plate structures and locking mechanisms are described below. These end-of-motion structures and fixation mechanisms are preferably incorporated into one or more artificial discs constructed as described above, or may be adapted for use or use with other known artificial discs.

  FIG. 11 illustrates an alternative form of an endplate 110 for use in an artificial disc that is configured for implantation by a minimally invasive, posterior implantation approach, such as described in the '276 application. The end plate 110 has a curved or kidney bean shape with two parallel keels 111a, 111b having a curvature similar to that of the end plate 110. A heel (not shown) having a similar keel morphology may also be usable. Since the curved shape of the artificial disc 336 (and heel) more closely matches the cross-sectional anatomy of the vertebral body, as illustrated in FIG. 12A by promoting rotation of the disc within the intervertebral space. Helps avoid nerves, blood vessels and other bone tissue along or adjacent to the grafting path 340 used during the posterior graft approach. Although two parallel implantation paths 340, one for each intervertebral disc 336, are shown, a single implantation pathway 340 may be used to implant both discs. The minimally invasive disc of the present invention may also be implanted by a posterior side or side approach method, as illustrated in FIG. 12B. Here, a single intervertebral disc 336 has been implanted through an implantation pathway 342 disposed in front of the transverse process. The illustrated intervertebral curvature also facilitates implantation by this approach as well.

  FIG. 13 shows an artificial intervertebral disc 350 that includes an upper end plate 352, a lower end plate 354, and a generally cylindrical core member 356. The generally cylindrical core member 356 can be fabricated from a hollow material so that the core member provides a thin state for selective contraction and deployment and then expands in its original position to the size and volume to operate. preferable. Alternatively, the core member may comprise a structure that is the same as or similar to that described with respect to FIGS. 4A-4C, for example.

  The upper end plate 352 and the lower end plate 354 are partially configured so that each inward surface of the end plate is generally concave and each outward surface of the end plate is generally convex. Each of the cylindrical shapes is preferred. Thus, the inwardly facing surface is adapted to engage and retain the generally cylindrical core member 356. In a particularly preferred embodiment, upper end plate 352 and lower end plate 354 each have a keel 358 formed or coupled to the upper and lower surfaces, respectively. The keel 358 is adapted to engage each vertebral body and secures the endplate for movement at the time of implantation.

  The aforementioned artificial discs may be implanted in separate parts or as a complete unit. In any case, the cylindrical core member 356 is preferably contracted or compressed prior to implantation and then expanded or expanded after implantation. The degree of expansion determines the physical properties of the core member 356, such as height, stiffness, and load bearing capacity of the core member. Selectable expansion of the core member provides a prosthetic disc 350 having a minimal deployed state that still has the required height, volume and size after expansion at the time of deployment.

  14A-14D show other alternative prosthetic discs 360 having a first thin state position for use when deploying the device and a second fully inflated state for use after deployment. Illustrate. The thin position is desirable for the deployment process because less bone tissue is removed during the posterior, minimally invasive implantation procedure. Removal of excessive bone tissue from the spine can lead to spinal instability and should be avoided if possible. On the other hand, it is preferable to have an artificial disc having a relatively large cross-sectional area after deployment. For example, if the artificial disc comprises upper and lower surfaces having a relatively small surface area, the disc tends to sink or sink into the bones of the upper and lower vertebral bodies.

  The artificial intervertebral disc 360 shown in FIGS. 14A-14D provides the ability to increase the surface area of the end-of-motion plate that interfaces with the post-implant vertebral body by raising adjacent superior and inferior surfaces. Referring to FIG. 14A, the upper end plate 362 includes a central portion 364 having a set of fixed fins 366 extending over at least a portion of the upper surface. The drop leaf 368 is rotatably coupled to each side surface of the central portion 364 along its entire length. Each drop leaf 368 may be screwed to the center by a hinge such as a standard continuous hinge, integral hinge 370 or other suitable mechanism. Each drop leaf 368 has a first delivery position (shown in FIG. 14A) where the drop leaf 368 extends downward from the edge of the central portion 364. Each drop leaf also has a second deployed position (shown in FIG. 14B), where the drop leaf 368 is part of the upper end plate by raising it so that it is flush with the central portion 364. Form. A drop leaf 378 is also formed in the lower endplate 372 having a central portion 374 as well. The lower endplate drop leaf 378 also has a first delivery position (shown in FIG. 14A) and a second deployed position (FIG. 14B).

  14C-14D illustrate a mechanism for supporting and stabilizing the drop leaf after it has been placed in the deployed position. FIG. 14D shows the upper drop leaf 368 positioned above the lower drop leaf 378, each in the deployed position. For clarity, the remainder of the artificial disc 360 is not shown in FIG. 14D. Each of the upper drop leaf 368 and the lower drop leaf 378 includes a spring slot 380 that extends onto an opposing surface. A separate spring 382 is shown in FIG. 14C. The separate spring 382 includes a first planar end 384a, a curved spring portion 386, and a second planar end 384b. After the drop leaf has moved to the deployed position after implantation of the artificial disc, the spring 382 is adapted to be installed in the spring slot 380 of the opposing set of upper and lower drop leafs. When in place, the spring 382 maintains the upper and lower drop leaf spacing, thereby providing a relatively large surface area for each of the upper and lower endplates.

  15A-15B illustrate an artificial intervertebral disc 390 having an elongated tubular core member 392 and a partially cylindrical upper motion end plate 394 and a partially cylindrical lower motion end plate 396. Each of the endplates includes a relief portion 398 at each of the front and back ends of the endplate. The relief portion comprises a partial cross-sectional view extending from the leading front and rear ends of each end plate. Compared to a similarly fabricated prosthetic disc without such a relief portion, the relief portion acts to provide enhanced flexion and extension of the artificial disc fabricated as described above.

  Referring to FIG. 15B, the fiber 400 is wound through a series of slots 402 formed at the respective ends of the upper end plate 394 and the lower end plate 396 to secure the end plate. Although non-uniformly spaced slots are provided as an alternative option, the slots 402 are evenly spaced along the end of the end plate. One or more fiber layers 400 may be used, and each fiber layer may be formed from different materials and / or different ranges of material properties such as stiffness. In some embodiments, the fibers 400 are wound up and down the core member and between the core and the end plate.

  Referring to the artificial discs shown in FIGS. 16A-16C, 17A-17B, 18A-18C, and 19A-19C, the artificial disc is a natural functional spinal unit physiology to the replacement disc. It is manufactured by a method that closely imitates. The spine is composed of motor segments, each composed of three joints with functional spinal column units simultaneously. The intervertebral disc and the two facet joints create spinal column stability and movement. The artificial disc will help to replace the natural disc. However, in many cases, conventional artificial discs do not suitably compensate for natural discs because they do not interact with facet joints in the same manner as natural discs. Furthermore, if the artificial disc is delivered to the spine by a posterior approach, the procedure may require partial or complete removal of the facet joint to gain access to the intervertebral space. This raises concerns regarding spinal stability and potential biomechanical disruptions that the artificial disc itself does not completely correct. The artificial discs shown in FIGS. 16A-16C, 17A-17B, 18A-18C, and 19A-19C not only provide natural disc function compatibility but also face joint function compatibility. Designed and manufactured to provide In this way, the present artificial disc provides adequate stiffness and mobility that exactly corresponds to the entire functional spinal unit.

  A set of artificial discs 410 is shown in top view in FIG. 16A. Each of the artificial discs 410 includes a generally bullet-shaped upper motion end plate 412 and a generally bullet-shaped lower motion end plate 414, each having a front end A and a rear end P. The prosthetic disc 410 also includes a front core member 416 and a rear core member 418 located between and supporting the upper and lower motion endplates. The front core member 416 and the rear core member are preferably generally cylindrical, as long as the front core member 416 is relatively larger than the rear core member 418 and highly rigid in the axial direction, as described in the front section or the '276 application. Any of the core member materials may be formed, and any of the core member structures may be included. The relatively large size and high rigidity of the front core member is determined by the choice of material, the configuration of the structure, the provision of fiber windings, or other mechanisms known elsewhere in the application or known to those skilled in the art. May be provided. In this manner, the anterior core member 416 provides many of the natural intervertebral physiological functions, and the posterior core member 418 provides the physiological functions of the facet joint. For example, as illustrated in FIG. 16B, the fiber winding 420a that is affixed to the front core member 416 is a relatively vertical pattern compared to the pattern of the fibers 420b that are wound around the rear core member 418. Contains wound fibers. Thus, the anterior core member portion of the intervertebral disc is rotationally more flexible than the posterior core member section as a natural intervertebral disc. On the other hand, the rear core member section is relatively rotationally rigid, like a natural face joint.

  In another alternative structure, a set of artificial discs 410 is shown in FIG. 16C. Each of the prosthetic discs has a generally curved shape such that each posterior end P of the prosthetic disc 410 is in a generally parallel arrangement, but each anterior end A of the intervertebral disc is in an adjacent arrangement opposite each other. Includes end plates 412, 414. In this arrangement, the front core member 416 is located closer to the sagittal midline as compared to the rear core member 418. Thus, the front portion of the combination of the two artificial discs is more rotationally flexible and is more flexible to lateral bending, corresponding to a natural disc. On the other hand, the rear part of the combination of two artificial discs is more rigid and rotationally inflexible, corresponding to a natural disc.

  Referring to FIGS. 17A-17B, another embodiment of an artificial disc 410 is shown. The artificial intervertebral disc includes an upper end plate 412, a lower end plate 414, and a set of core members 416, 418 positioned and supported between the end plate. The upper end plate 412 includes a fixed fin 422, and the lower end plate also includes a fixed fin 424. The first fiber winding 420 a is positioned around the front core member 416, and the second fiber winding 420 b is positioned around the rear core member 418.

  The upper end plate includes a surface 426 extending downward at the rear end. Similarly, the lower end plate includes a surface 428 extending upward at the rear end. The upper surface 426 and the lower surface 428 together form a set of conforming surfaces that mimic the restrictive function of the natural face joint translational motion. For example, in the embodiment shown in FIG. 17A, the upper surface 426 has a back-angled surface 427 and the lower surface 428 has a front-angled surface 429. In the embodiment shown in FIG. 17B, the upper surface 426 and the lower surface 428 have vertical surfaces. Due to the spatial relationship, the two opposing surfaces prevent the upper motion endplate 412 from translating forward and the lower motion endplate 414 from translating backward.

  The gap 430 is preferably maintained between the lower end of the upper surface and the lower movement end plate, and between the upper end of the lower surface and the upper movement end plate. The gap 430 determines the spatial distance available to bend and extend due to the force applied by the artificial disc. In the angulated structure shown in FIG. 17A, the upper and lower motion endplates are more heavily loaded and the mating surfaces engage with greater force as the prosthetic discs face compression displacement. Therefore, the conforming surface is preferably made from a highly wear resistant material.

  17B shows an optional gasket 432 in the embodiment illustrated in FIG. 17B. The gasket 432 functions to prevent tissue ingrowth into the artificial disc 410 or to seal the internal space of the artificial disc.

  Referring to FIGS. 18A-18C, another embodiment of an artificial disc 410 is shown. Each of the artificial intervertebral discs is an upper motion end plate 412, a lower motion end plate 414, and a pair of core members positioned between and supporting the upper motion end plate and the lower motion end plate (in any of FIGS. 18A to 18C). (Not shown). Upper end plate 412 includes a mating surface 426 that extends downward, and lower end plate 414 also includes a mating surface 428 that extends upward. In these embodiments, the conforming surface is provided in an offset manner at the external posterior corner of each of the two artificial discs. Alternatively, these conforming surfaces are the same as described above with respect to FIGS. 17A-17B. The offset position of the mating surface provides a mechanism that mimics the torsional resistance obtained by natural surface joints.

  For example, as shown in the posterior surface shown in FIG. 18B, the contact surfaces of the fitting surfaces 426 and 428 of the artificial disc 410 located on the right side of the figure are the end of the upper motion to the left and the front with respect to the lower motion end plate 414. Resist the movement of the plate 412. Similarly, the contact surfaces of the prosthetic disc mating surfaces 426, 428 located on the left side of the figure resist movement of the upper motion end plate 412 to the right and forward relative to the lower motion end plate 414. The opposite horizontal resistance arrangement is obtained by reversing the relative arrangement of the mating surfaces, as shown in FIG. 18C.

  The physiological functions of anterior-posterior resistance and torsional (lateral) resistance normally performed by natural facet joints may be mimicked by the material, structure and placement of the artificial disc core structure. With reference to FIGS. 19A-19C, several alternative structures for performing these functions are described. For example, FIG. 19A shows a set of artificial discs 410 in a parallel relationship with each other. Each artificial disc includes an upper motion end plate 412, a lower motion end plate 414, a front core member 416, and a rear core member 418. As shown in FIG. 19A, the posterior core members 418 of the two artificial discs are each concentrated at the posterior end of each intervertebral disc, each being relatively larger than each anterior core member 416. Each of the front core members 416 is located in the vicinity of the inner end of the end plate of movement, thereby setting the centers of the front core members 416 relatively closer to each other than the center of the rear core member 418. In this arrangement, relatively small front core members 416 that are positioned relatively close to each other are relatively more than allowed by a relatively large rear core member 418 that is further spaced compared to the front core member. Provides a large amount of twist. In this way, the illustrated arrangement creates translational and torsional resistances intended to mimic the natural physiological forces applied by the functional spinal unit.

  Similarly, in the artificial disc 410 illustrated in FIG. 19B, the fibers 420a and 420b are wound in a pattern surrounding each of the front core member 416 and the rear core member 418 of the set of artificial discs. In the intervertebral disc on the left side of the figure, the posterior core member 418 is wound with more fibers 420b than the fiber winding 420a surrounding the anterior core member 416. This results in a relatively greater limit to twist or translation at the posterior end P of the disc than is possible at the anterior end A of the disc. In the intervertebral disc on the right side of the figure, the fiber turns 420a, 420b are concentrated at the anterior and posterior edges of the artificial disc.

  Finally, in the artificial disc 410 illustrated in FIG. 19C, the front core member 416 is relatively longer than the rear core member 418. Each core member is provided with the surrounding fiber wound layers 420a and 420b. The relatively long front core member 416 allows a relatively greater amount of translation and rotation freedom than is possible with the relatively short rear core member 418.

  Advantageously, some of the characteristics described above with respect to the artificial discs shown in FIGS. 16A-16C, 17A-17B, 18A-18C, and 19A-19C may be used in combination with other combinations to provide a functional spine. A desired biomechanical regeneration of the unit may be obtained.

  Referring to FIGS. 20-21 below, an exercise end plate 430 comprising an outer exercise end plate 432 and an inner exercise end plate 434 is illustrated. An outline of the design and structure of the end plate is described in the '276 application. The inner end plate 434 has a column 436 extending through a fitting hole 438 in the outer end plate 432 and a storage portion 442 formed on the inner surface of the outer end plate 432. A peripheral edge 440 is included. The inner end plate 434 is then welded to the outer end plate 432 with posts 436 and peripheral engagement surfaces 440. In conventional designs, a large amount of stress is generated in the weld joint that connects the inner and outer endplates. In the designs illustrated in FIGS. 21-21, the inner end plate includes four peripheral wings 444 extending radially outward at equally spaced locations around the inner end plate 434. Similarly, outer end plate 432 includes four mating receptacles 446 adapted to receive and hold wings 444 formed on the inner end plate. The inner end plate 434 is then welded to the outer end plate 432 at the location of the contact surface between the extension 444 and the storage portion 446, thereby distributing the stress over a large area.

  An alternative structure for joining the upper and lower endplates is shown in FIG. The artificial intervertebral disc 410 includes an upper motion end plate 412, a lower motion end plate 414, and a core member 416. This general structure may comprise any of the specific embodiments described above, those described in the '276 application, or others known in the art. The plurality of fibers 420 extend between the upper end plate 412 and the lower end plate 414 around the core member 416, and are connected to each of them. The fibers 420 provide structural integrity to the artificial disc 410 and hold the motion endplates together on opposite sides of the core member 416.

  In order to better mimic the physiological function of the natural disc, the artificial disc 410 shown in FIG. The outermost fiber layer 421 is preferably formed using relatively rigid and inelastic fibers. On the other hand, the innermost fiber layer 423 is preferably formed using fibers that are more flexible and elastic. The intermediate layer of fibers is preferably formed from fibers having an intermediate range of stiffness and elasticity.

  Provide more or less fiber layer 420 while providing the same or similar performance by providing more rigid fibers at the outer periphery and arranging relatively flexible fibers inside the artificial disc It is contemplated that it may be included. Alternatively, the stiffness range may be reversed, such as providing higher stiffness fibers in the intervertebral disc near the core member and gradually providing fibers with lower stiffness towards the outer periphery of the disc. Other variations are also contemplated.

(IV. End plate fixation mechanism)
A number of suitable mechanisms for securing the endplates to the vertebral body are described below. These fixation mechanisms are typically adapted for use with the motion endplates incorporated into the artificial discs described herein and elsewhere. Other uses for these securing mechanisms will also become apparent upon review of the following description.

  Referring first to FIGS. 22A-22D, a motion endplate 450 for use with an artificial disc includes a plurality of fixed fixation fins 452 on the outer surface. Fixed fixation fins 452 are adapted to engage grooves that are cut into the inwardly facing surface of the vertebral body, for example, as described in the '276 application. Although these fixation fins 452 are intended to fix and engage the endplates to the vertebral body, it is common for the fixation fins 452 to be movable inside the groove. In the process, the artificial disc moves from the preferred position.

  To improve this situation, retractable or movable spikes 454 or fins 456 are placed on the endplate 450 in a manner that allows selective engagement. Retractable or movable fins 456 provide additional fixation to the vertebral body. Advantageously, the retractable or moveable fins 456 are arranged at an angle, preferably at a right angle, with respect to the stationary fixed fins 452 located on the outer surface of the end plate. In this way, when they are engaged, the retractable or moveable fins 456 prevent unwanted movement of the motion endplate 450 and thus the artificial disc. For example, FIG. 22A illustrates a top view showing a stationary fixed fin 452 and a plurality of retractable fins 456, each in an extended state. FIG. 22B is a cross-sectional view illustrating fixed stationary fin 452 and retractable fin 456, which are also in an extended state.

  Retractable fin 456 may be moved from the undeployed state to the deployed state by one of many suitable mechanisms. For example, the inflation balloon 458 may be deployed between the upper motion end plate 450 and the lower motion end plate 460 after deployment. For example, see FIG. 22D. The inflatable balloon may be inflated to move the retractable fins 456 from the undeployed state to the deployed state that extends outwardly from the outwardly facing surfaces of the motion endplates 450,460. Other mechanical spacers or screw-type devices 462 can be used as an alternative method for performing the deployment function. For example, see FIG. 22C.

  Referring now to FIGS. 23A-23B, a partially cylindrical endplate 470 and removable keel 472 are shown. The partially cylindrical end plate 470 is generally similar to that described above with respect to FIGS. 13 and 15A-15B. The removable keel 472 is an elongated member having a generally triangular cross section. The triangular cross-section base 474 of the keel 472 is adapted to engage an elongated trapezoidal slot 476 formed in the upper surface of the endplate. Accordingly, end-of-motion plate 470 may initially be deployed without using removable keel 472 so as to minimize the side of the end-of-motion plate for implantation. Once implanted, the keel 472 may be coupled to the end plate 470 by sliding the keel base 474 into the trapezoidal slot 476 in the longitudinal direction. The keel 472 is then in a position to engage the surface of the vertebral body so as to secure the end-of-motion plate in an appropriate position relative to the vertebral body when the artificial disc is deployed.

  A selectively deployable locking screw and associated mechanism are shown in FIGS. 24A-24B and 25A-25C. The fixation screw 480 is adapted for use with an artificial disc having a motion endplate 482 formed from an inner motion endplate portion 484 and an outer motion endplate portion 486, wherein the inner motion endplate portion 484 is an outer motion. It is rotatable with respect to the end plate portion 486. The screw fixation 480 is located in a slot 488 formed in the medial endplate 484 of the artificial disc. The screw is retained in the slot 488 so that the fixation screw 480 can move axially within the slot but cannot rotate relative to the inner motion endplate 484. The outer motion end plate 486 includes a screw hole 490 from which a fixing screw 480 extends. Accordingly, rotation of the inner end plate 484 relative to the outer end plate 486 advances the locking screw 480 through the slot 488 in the inner end plate and out of the hole 490 in the outer end plate.

  FIG. 24B illustrates a mechanism 492 adapted to achieve rotation of the inner end plate 484 relative to the outer end plate 486 as described above. The mechanism 492 includes an elongate actuator 494 having a plurality of teeth 496 formed along its edges. Inner motion endplate 484 also includes teeth 485 adapted to mate with actuator teeth 496. When the teeth are engaged, advancement of the actuator 494 causes rotation of the inner motion end plate 484 relative to the outer motion end plate 486, thereby causing the retractable fixation screw 480 to extend outward and engage the vertebral body. . When the actuator 494 is pulled out (while the teeth are engaged), the fixing screw retracts.

  25A-25C illustrate an artificial disc 500 having a similar retractable fixation mechanism structure. The artificial intervertebral disc 500 includes an upper motion end plate 502, a lower motion end plate 504, and three core members 506 positioned between the upper motion end plate and the lower motion end plate. Each core member 506 includes a compressible inner member 508, which may optionally be spring loaded, and an upper fixing member 510 and a lower fixing member 512. The stationary assembly is such that rotation of an inner motion end plate member (not shown) associated with each of the three core members 506 (see FIG. 25B) causes each of the fixing members 510, 512 to move to the respective outer motion end plate. It is manufactured to extend outward through a hole 514 on the outer surface of (see FIG. 25C).

  The retractable fixation screw structure described above provides the ability to deliver a relatively thin prosthetic disc, for example, during a minimally invasive implantation procedure. As shown in FIG. 25A, the prosthetic disc 500 has a relatively short length prior to extension of the fixation screws 510, 512. If the artificial disc is implanted in this state, it is not necessary to remove a large amount of spine, allowing access to the disc space. Furthermore, there is less chance of causing damage to adjacent tissues such as nerves during insertion. After insertion, for example, as shown in FIGS. 25A-25B, retractable fixation screws 510, 512 extend to secure the artificial disc to the adjacent vertebral body.

  Other alternative securing mechanisms are shown in FIGS. 26A-26C. This mechanism is also intended to provide a thin structure during the implantation procedure. The thin state reduces the potential for tissue or nerve damage caused by the fixation mechanism and, in the case of posterior transplants, reduces the size of laminectomy and spine arthrotomy required to accommodate the transplant .

  Referring to FIG. 26A, a set of artificial discs 520 after posterior minimally invasive implantation is illustrated. Each of the artificial discs 520 is generally diamond-shaped and the set is provided in a parallel arrangement within the disc space. A plurality of fixed spikes 522 extend radially outward from each side of the artificial disc. The spike extends and engages the rest of the natural disc that remains in the disc space after implantation of the artificial disc. Preferably, the spikes 522 have a spring mechanism (not shown) that causes each spike to bend outwardly to a deployed position (FIG. 26C) that extends from a rearward delivery position (FIG. 26B) after implantation of the artificial disc. Prepare. Other actuation mechanisms are further contemplated. For example, alternative actuation mechanisms include screw mechanisms that are assembled by the user at the posterior end of each artificial disc. The rotation of the screw mechanism is translated by the connection, causing each spike to extend to the deployed position.

  The lateral placement of the fixation spike 522 shown in FIGS. 26A-26C may provide sufficient retention force to serve the function of fixing the artificial disc in place. More lateral spikes may be added to the structure if additional securing force is required. Alternatively or additionally, fixation fins may be included on the outer surfaces of the upper and lower endplates to engage the inner surface of the vertebral body. Further fixation may be provided by joining or surgically stapling the disc to the remaining natural disc.

  Other embodiments of selectively removable fixing members are shown in FIGS. 27A-27C. The fixation member includes an insertable keel structure 530 adapted to selectively couple to an outer surface of a motion endplate of an artificial intervertebral disc such as the motion endplate described herein, the '276 application, and elsewhere. Prepare. The keel 530 includes a base 532 and a fixed fin 534 that extends upwardly from the top surface of the base. The coupling member 536 is formed on the bottom surface of the base 532. In the illustrated embodiment, the coupling member 536 is adapted to slide into a mating trapezoidal slot formed in the outer surface of the end plate, thereby coupling the keel 530 to the end plate. It is outing. Although more or fewer vertices may be provided, the fixed fin includes three vertices 538a-538c. The fins 534 are adapted to physically engage the inner surface of the vertebral body, thereby holding the artificial disc in place.

  Advantageously, the removable keel base 532 is in the form of a generally wedge-shaped member having an upper surface located in a plane at an acute angle β with respect to the plane of the lower surface of the base. The purpose of the removable keel wedge is to provide an anterior lordosis angle to accommodate the angle between the vertebral bodies, especially in the case of lumbar artificial disc implantation. In this way, the endplates of the prosthetic discs may be provided in parallel relation to each other, and the removable keel provides a preferred lordosis for the prosthetic disc structure.

(V. Artificial intervertebral disc system)
A number of systems and optional functions that may be incorporated or merged into an artificial disc are described below.

  Referring initially to FIGS. 29A-29B, a system for keeping an artificial disc thin during an implantation procedure is shown. The system includes an upper end plate 552, a lower end plate 554, and an artificial disc 550 having a core member 556 positioned between and coupled to the upper end plate and the lower end plate. The holding mechanism 558 extends between the upper motion end plate 552, the core member 556, and the lower motion end plate 554. Preferably, the retention mechanism 558 extends through a hole formed in each of the upper and lower endplates 552, 554 for purposes and the channel passes through the core member 556.

  The retention mechanism 558 operates to selectively keep the artificial disc 550 in a compressed, thin state. In particular, the retention mechanism 558 includes a shaft 560 extending through the artificial disc, an upper coupling mechanism 562 that couples the shaft 560 to the upper motion end plate 552, and a lower coupling mechanism 564 that couples the shaft 560 to the lower movement end plate 554. including. An example of a coupling mechanism is shown in FIG. 29B, where the end of the shaft 560 includes a V-shaped notch 561 that engages a keyhole 566 formed in the locking plate 568. The locking plate 568 is slidably coupled to one or both of the upper end plate 552 and the lower end plate 554, and a V-shaped notch 561 at the end of the shaft 560 engages the keyhole 566, and the locking plate 568. Against the shaft 560 in place. When the locking plate 568 slides, the shaft 560 can pass through the keyhole 566, releasing the holding mechanism. Other coupling mechanisms are also contemplated.

In practice, prior to implantation, the artificial disc 550 is compressed to a reduced height relative to the operable height. The retention mechanisms 562, 564 are then engaged to effectively inhibit the compressed disc from expanding to an operable height.
The compressed disc is then implanted, preferably by a minimally invasive surgical procedure.
When the intervertebral disc is placed in the intervertebral space, the retention mechanisms 562, 564 are released, for example, by sliding the locking plate 568, opening the end of the shaft 560 through the keyhole 566. Therefore, the artificial intervertebral disc without suppression returns to the operable height and becomes operable.

  Referring to FIG. 30 below, a core structure for use in a spinal implant device is shown. The core structure is adapted to provide a method for adjusting the torsional stiffness of the spinal implant device. For example, the core structure includes a generally cylindrical core member 570 formed from materials such as those described above and by methods. The core member includes a plurality of substantially cylindrical storage portions 572 extending downward from the top surface of the core member and upward from the bottom surface of the core member. Thus, the core member 570 is configured to engage the upper motion end plate having a plurality of mating generally cylindrical pins extending downwardly from the inner surface of the upper motion end plate. Thus, the core member 570 is configured to engage the upper motion end plate having a plurality of mating generally cylindrical pins extending downwardly from the inner surface of the upper motion end plate. The core member is rotationally fixed to both the movement end plates by the interaction between the storage portion formed in the core member and the pins formed on the inner surfaces of the upper movement end plate and the lower movement end plate.

  Advantageously, the number, size, shape, material and material properties of the core member receptacle 572 and mating endplate pins are subject to design choices to achieve the desired properties. For example, a relatively shallow receptacle 572 may be provided and a relatively short pin may be provided to obtain a relatively low torsional stiffness between the core member and the end plate. Increasing the length of the storage portion 572 and the end plate of the movement tends to increase the degree of torsional rigidity. Other variations are also contemplated, including the location of the pin (and storage) relative to the central axis of the endplate. Furthermore, in order to obtain other desired results, the storage portion 572 may be formed on the movement end plate, or the pins to be fitted may be formed on the upper surface and the lower surface of the core member.

  With reference to FIGS. 31A-31D below, a preferred system of spinal motion maintenance devices is shown. Spinal motion maintenance devices are used to treat spinal diseases or conditions. Two types of such maintenance devices are total artificial discs and dynamic stabilization devices. These devices are used, for example, to treat degenerative disc disease and spondylolisthesis. Such devices are used independently but are not used together in the manner described herein.

  For example, FIG. 31A shows a dynamic stabilization device 580 coupled to the transverse processes 582, 584 of a set of adjacent vertebral body portions 586, 588. The dynamic stabilization device 580 includes an upper coupling member 590 (such as a pedicle screw) that provides coupling to the upper vertebral body 586, and a lower coupling member 592 (such as the pedicle) that provides coupling to the lower vertebral body 588. And a stabilizing portion 594 extending between and connected to the upper coupling member 590 and the lower coupling member 592. The structural and functional details of the dynamic stabilization device 580 are outside the scope of this description. Most are generally known to those skilled in the art and are generally available in industry literature.

  The artificial disc 600 is located in the intervertebral space between the two vertebral body parts 586 and 588. The natural intervertebral space 610 is located in the intervertebral space above and below the artificial disc 600. Artificial intervertebral disc 600 includes upper end plate 602, lower end plate 604, and core member 606 extending between upper end plate 602 and lower end plate 604 and coupled thereto. The artificial intervertebral disc 600 may be fabricated according to any of the embodiments described herein, in the '276 application, or elsewhere.

  One or more motion maintenance devices (including artificial discs, dynamic stabilization devices, interspinous spacers, etc.) may also be combined with an exchange device such as a facet joint or vertebral body replacement.

  A “rhombus” artificial disc 620 is shown in FIG. 31B. The intervertebral disc 620 extends between the upper end plate 622 having a plurality of fixed fins 623, the lower end plate 624 having a plurality of fixed fins 625, and the upper end plate and the lower end plate. Includes a set of core members 626a, 626b that are similar to those described above and in the '276 application. The “diamond” shaped artificial disc 620 is particularly adapted to be implanted by minimally invasive surgical procedures using posterior access. The previously described artificial disc 620 is suitable for use in combination with one or more dynamic stabilization devices 580 in the manner described above.

  Alternatively, as shown in FIGS. 31C-31D, the artificial disc 620 and the dynamic stabilization device 580 may be merged into an integrated structure. FIG. 31C shows a prosthetic disc 620 having a pair of core members 626a-626b extending between and coupled to the upper end plate 622, the lower end plate 624, and the upper end plate and the lower end plate. 1 illustrates a first embodiment of such a device. The artificial disc is a “diamond” shape similar to that described above with respect to FIG. 31B. As shown in FIG. 31D, in an alternative embodiment, the prosthetic disc 630 includes an upper motion end plate 632 and a lower motion end plate 634 that are angled to facilitate device insertion in a minimally invasive surgical procedure. The dynamic stabilization device 580 is coupled to the posterior side of the artificial disc 630. The dynamic stabilization device 580 can suppress movement of the vertebral body that is coupled to one or both of the axial and lateral directions and adapts to various anatomical structures.

  Referring now to FIGS. 32A and 32B, where two or more artificial disc implants are used within a single disc space, the discs may be spaced apart or engage one another. In the latter case, the engagement may be end to end, side to side, or end to side. In order to facilitate positioning and placement of two or more intervertebral discs relative to each other, one or more components or portions of components may be configured to be coupled together. For example, the peripheral edge of one or more endplates or the sides of the gasket may be locked to maintain a fixed engagement between the discs. FIG. 32A shows an intervertebral disc end-of-motion plate 110 having a fluted nail tongue and groove configuration 640. Similarly, the intervertebral disc gasket 132 of FIG. 32B is configured with a connecting bellows 650. Each of these coupling mechanisms facilitates the positioning and placement of adjacent artificial discs relative to each other.

  33A-33C illustrate a prosthetic disc mechanism adapted to deploy in a generally X-shaped configuration. The generally X-shaped configuration is believed to provide a better placement of the center of rotation and provide support for lateral bending, bending, and extension. As shown in FIG. 33A, the generally X-shaped configuration is a set of curved surfaces arranged such that the curved tip 662 of each disc is directed toward each other and is located near the center 664 of the disc space. It may be obtained by providing an artificial disc 660.

  Alternatively, as shown in FIGS. 33B-33C, each of the artificial intervertebral discs may comprise an upper end plate and a lower end plate, each having a central (or off-center) connection 670. . The core member is positioned between the upper motion end plate and the lower motion end plate, and is preferably coupled to either one of the side portions of the connecting portion. As shown in FIG. 33B, the artificial disc may be implanted while in a linear configuration, thereby minimizing the aspect of the implantation. Then, after implantation, the artificial disc may be curved by pivoting the end of the disc through the connection 670 to form a curved artificial disc such as that shown in FIG. 33A.

  34A-34B illustrate a surgical method for implanting an artificial disc using a single implantation, single-sided posterior approach. As shown, for example, in FIG. 34A, posterior access 680 is created in disc space 682 and the cannula is inserted to maintain access. A generally diamond shaped artificial disc 686 is inserted through the cannula 684 into the disc space 682 with the longitudinal axis extending in the same axis as the cannula. An insertion tool 688 having a gripping end 690 facilitates the insertion of the artificial disc 686. As shown in FIG. 34A, at the time of initial insertion, the artificial disc 686 is offset by 90 degrees from the desired placement in the disc space 682.

  Referring to FIG. 34B, the prosthetic disc misalignment is accomplished by using the insertion tool 688 to grip the disc and rotating it 90 degrees until the longitudinal axis of the prosthetic disc is perpendicular to the insertion path. It is corrected by rotating. After rotation, the artificial disc 686 is in proper placement within the disc space 682.

  35A-35D illustrate an alternative minimally invasive surgical procedure for implantation of one or more artificial discs. The illustrated procedure uses a rear approach or a side approach that avoids some of the disadvantages inherent to the forward approach. As shown in FIG. 35A, the cannula 700 is inserted laterally through the side of the patient to provide access to the disc space 702. A set of generally diamond-shaped artificial discs 704a-704b are aligned for insertion through the cannula into the disc space.

  Referring to FIG. 35B, when the leading artificial disc 704a pushes the cannula 700 into the disc space 702, the distal end of the subsequent artificial disc 704b is positioned at the proximal end of the leading artificial disc 704a at an angle. Contact. The subsequent artificial disc 704b rolls forward while the angular contact causes the leading artificial disc 704a to roll backward into the disc space 702. (See FIG. 35C) After the subsequent artificial disc 704b is further advanced, the leading disc 704a and the subsequent disc 704b reach a final parallel configuration, as shown in FIG. 35D.

  FIGS. 36A-36J illustrate some embodiments of a connection mechanism suitable for connecting a set of adjacent artificial discs 710, such as those described above with respect to FIG. 35D. Referring initially to FIGS. 36A-36B, these views illustrate a side view and a top view, respectively, of a first artificial disc 710 having a first coupling mechanism 712. The first coupling mechanism 712 is in the form of a plurality of pins projecting from the sides of the prosthesis upper and lower motion endplates 714, 716. As shown in the illustrated example, the two pins project from the respective sides of the upper end plate 714 and the lower end plate 716. More or fewer pins may be suitable.

  36C-36D, which illustrate a side view and a top view, respectively, of a second artificial disc 720 having a second coupling mechanism 722, the second coupling mechanism comprising: It is complementary to the first coupling mechanism 712 shown in FIGS. 36A-36B. The second coupling mechanism 722 is in the form of a tilting table that forms a plurality of harmonized corners projecting from the respective sides of the prosthesis upper and lower endplates 724, 726.

  Referring now to FIGS. 36E-36F, which illustrate a side view and a top view, respectively, of a third artificial disc 730 having a third coupling mechanism 732, which also includes a third coupling mechanism 732. Similarly, it is complementary to the first coupling mechanism 712 shown in FIGS. 36A-36B. The third coupling mechanism 732 is in the form of a plurality of harmonious C-shaped clamps projecting from the respective sides of the prosthesis upper and lower endplates 734, 736.

  FIG. 36G shows first and second artificial discs 710, 720 represented in FIGS. 36A-36B and 36C-36D, respectively, which are shown in FIGS. 36A-36B. Partially assembled with a pin of one coupling mechanism 712, said pin moving laterally and slightly downward to the right, second moving to the left and slightly upward as shown in FIGS. 36C-36D The coupling mechanism 722 is partially engaged with the inclined base. Two components fully assembled to drop the pin behind the back of the ramp, thereby preventing the prosthesis pin from moving to the left of the half end and the right end of the prosthesis ramp half This intervertebral disc prosthesis is shown in FIG. 36H. 36I shows the protruding pin of the first coupling mechanism 712 represented in FIGS. 36A-36B that snaps completely into the protruding clamp of the third coupling mechanism 732 represented in FIGS. 36E-36F. 36B shows an alternative third coupling mechanism 732 depicted in FIGS. 36E-36F, fully assembled with the first artificial disc 710 depicted in FIGS. 36A-36B. It will be appreciated by those skilled in the art that the engaging coupling mechanism shown in FIG. 36I prevents the movement of the two half ends of the prosthesis relative to each other both laterally and vertically in both directions.

  Referring now to FIGS. 37A-37F, another embodiment of a minimally invasive surgical procedure for delivering a set of artificial disc implants is illustrated. The procedure is intended to provide a repeatable placement of the implanted disc. The final location deformation of the implanted artificial disc relative to each other and to the vertebral body creates a variation in the biomechanical performance of the implanted disc, thus producing a relatively consistent implantation result. Preferably a method is provided.

  The procedure may be adapted for use with an artificial disc 740 such as the embodiment shown in FIG. 37A. Intervertebral disc 740 extends between upper motion end plate 742 with optional fixation fins 743, lower movement end plate 744 with optional fixation fins 745, and upper and lower movement end plates, respectively. A core member 746 is included. A guide channel 748 is formed in each of the upper end plate and the lower end plate. Guide channels 748 preferably extend through the entire length of each endplate. A guide wire 750 is shown in FIG. 37B. The guide channel 748 formed in each of the upper end plate 742 and the lower end plate 744 of the artificial disc 740 is large enough to allow the guide wire 750 to pass through. Guidewire 750 is preferably formed from a braid, winding, or monofilament material.

  Before beginning, the surgical procedure requires the creation of access to both sides of the posterior disc space 760. A set of cannulas 762, 764 are inserted into the incision to provide access. The nucleus of the natural disc and the lateral and anterior rings are removed (see FIG. 37C). Guidewire 750 is then injected into one of the access channels and exits through the hollow core cavity and out of the opposite access channel. When the guidewire 750 is in place, as shown in FIG. 37D, the artificial discs 740a, 740b advance as each of the ends of the guidewire 750 is sewn, and a set of artificial discs 740a-740b. Advances over the guidewire 750 into the hollow core cavity 760. In a preferred embodiment, the guidewire 750 includes a set of fixation stops 752a-752b that prevent the artificial disc 740 from proceeding further along the guidewire 750. Thus, if the guidewire 750 is properly positioned within the disc space, each of the artificial discs will advance relative to each other to a predetermined location within the disc space.

  In a particularly preferred embodiment of the foregoing method, each of the artificial discs 740a-740b is formed in a “J” shape, each including a set of core members 746a-746b. See Figure 37E. In this embodiment, as shown in FIG. 37F, at the time of final implantation, the distal ends of the discs abut each other (see point 749) within the disc space.

  38A-38F illustrate some embodiments of the set of “J” shaped artificial discs 740a-740b described above. The set of discs shown in these figures includes a coupling mechanism that provides the ability to couple the set of discs 740a-740b together after deployment. For example, in FIGS. 38A-38B, the first artificial disc 740a includes a storage 772 formed in the second artificial disc 740b and an enlarged extension 770 that is sized to provide snap-fit engagement. . When the distal ends of the intervertebral discs are pressed together, the extension 770 is inserted into the storage 772 and snaps in place, thereby joining the first disc 740a to the second disc 740b. Similarly, in FIGS. 38C-38D, the first artificial disc 740a is adapted to engage and couple with a mating slot 782 formed at the distal end of the second disc 740b. Is provided with a hook extension 780. Finally, in FIGS. 38E-38F, a suture 790 is inserted through the id channel 748 formed in each of the first artificial disc 740a and the second artificial disc 740b. As the distal ends of the intervertebral discs are pressed together, knots 792 are tied at the respective ends of suture 790 to maintain the relative position of the set of artificial discs. Alternatively, clips may be attached to each end of the suture. The end of the suture line may then be cut away to remove any excess material. Furthermore, the guide wire can fold the pleats at both ends and cut away unnecessary portions.

  Referring to FIG. 39, an encapsulated spring disc replacement system 800 is shown. The system includes an internal spring element 802 contained in an elastomer capsule 804. The spring element 802 may comprise a leaf spring (eg, oval or leaf spring), a spiral spring, a chord spring (eg, a coil spring), or the like. Spring element 802 may be formed from a metal material (eg, stainless steel, metal alloy), an elastomeric material, or any other suitable material. The spring element 802 is preferably coupled to an upper (upper) fixing member 806 and a lower (lower) fixing member 808. Upper and lower fixation members 806, 808 are suitable for engaging the upper and lower vertebral bodies to substantially secure the spike or fin, anchor, or disc replacement system in place as shown. Any other member may be provided. Examples of suitable fixing members are described above. Elastomeric capsule 804 may be generally spherical, cubic, kidney-shaped, or any other size or shape suitable for the intended application.

  Each encapsulated spring system 800 may be implanted by cannula delivery by compressing the spring element 802 to reduce the shape of the system 800. The encapsulated spring system 800 may then be expanded to a normal state after delivery. In this way, the encapsulated spring system is suitable for deployment and implantation between a set of adjacent vertebral bodies. A single encapsulated spring system or multiple small such systems may be implanted as a partial disc replacement or to provide disc assistance or disc correction. Alternatively, a relatively large number of encapsulated spring systems may be implanted to provide total disc replacement.

(VI. Information about explanation included in this application)
It is to be understood that the invention which is the subject of this patent application is not limited to the specific embodiments described, as such may naturally vary. Since the scope of the present invention is limited only by the appended claims, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. It will be further understood.

  Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or similar to those described herein can also be used in the practice and testing of the present invention, the preferred methods and materials are described herein.

  All patents, patent applications and other publications mentioned in this application are hereby incorporated by reference in their entirety. The patents, applications, and publications described in this application provide only disclosures prior to the filing date of the present application. Nothing in this application shall be construed as an admission that the invention is not entitled to an invention before the date of those publications because it is a prior invention. In addition, the stated publication date may differ from the actual publication date and may need to be individually confirmed.

  As will be apparent to those of skill in the art upon reading this disclosure, each individual embodiment described and illustrated herein has separate components and features, and others without departing from the scope or spirit of the invention. May be easily separated or combined with features of any of the embodiments.

  The foregoing merely illustrates the principles of the invention. Although not explicitly described or illustrated herein, it will be understood by those skilled in the art that various arrangements can be devised which embody the principles of the present application and fall within the spirit and scope thereof. Further, all examples and conditional languages listed in this application are primarily intended to assist the reader in understanding the principles of the invention and the concepts provided by the inventor in order to develop the art. It should be construed that the invention is not limited to the specifically listed examples and conditions. Furthermore, as well as specific examples of the invention, all statements in this application that enumerate the principles, aspects, and embodiments are intended to encompass both their structural and functional equivalents. Furthermore, such equivalents are intended to include both presently known equivalents and future developed equivalents, ie, any element developed to perform the same function regardless of structure. Accordingly, the scope of the invention is not intended to be limited to the example embodiments illustrated and described herein. Rather, the scope and spirit of the invention is embodied by the appended claims.

1A and 1B provide a three-dimensional view of two different artificial discs according to the present invention. 1A and 1B provide a three-dimensional view of two different artificial discs according to the present invention. FIG. 2 provides a three-dimensional view of a fiber compressible element comprising a polymer core and a fibrous ring, according to one embodiment of the present invention. FIG. 3 provides a three-dimensional cross-sectional view of the artificial disc. 4A-4B provide three-dimensional views of two embodiments of the core member. 4A-4B provide three-dimensional views of two embodiments of the core member. FIG. 4C provides an end view of the core member located between the set of end plates. 5A-5B provide a side view of an artificial disc having a core in the form of a plurality of core members. 5A-5B provide a side view of an artificial disc having a core in the form of a plurality of core members. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 6A-6N and 6P-6T provide illustrations of several embodiments of core members suitable for use in the artificial discs described herein. 7-10 provide illustrations of some embodiments of adjustable core structures. 7-10 provide illustrations of some embodiments of adjustable core structures. 7-10 provide illustrations of some embodiments of adjustable core structures. 7-10 provide illustrations of some embodiments of adjustable core structures. FIG. 11 provides a top view of the end plate. 12A-12B provide an illustration of a method for implanting an artificial intervertebral disc having a motion end plate as shown in FIG. 12A-12B provide an illustration of a method for implanting an artificial intervertebral disc having a motion end plate as shown in FIG. FIG. 13 provides a perspective view of an artificial disc having a generally elongated tubular core member. 14A-14D provide an illustration of a selectively expandable artificial disc and its components. 14A-14D provide an illustration of a selectively expandable artificial disc and its components. 14A-14D provide an illustration of a selectively expandable artificial disc and its components. 14A-14D provide an illustration of a selectively expandable artificial disc and its components. 15A-15B provide an illustration of an artificial disc having an elongated tubular core member. 15A-15B provide an illustration of an artificial disc having an elongated tubular core member. 16A-16C, 17A-17B, 18A-18C, and 19A-19C provide an illustration of an artificial disc configured to mimic the physiology of a natural functional spinal unit. . 16A-16C, 17A-17B, 18A-18C, and 19A-19C provide an illustration of an artificial disc configured to mimic the physiology of a natural functional spinal unit. . 16A-16C, 17A-17B, 18A-18C, and 19A-19C provide an illustration of an artificial disc configured to mimic the physiology of a natural functional spinal unit. . 16A-16C, 17A-17B, 18A-18C, and 19A-19C provide an illustration of an artificial disc configured to mimic the physiology of a natural functional spinal unit. . 16A-16C, 17A-17B, 18A-18C, and 19A-19C provide an illustration of an artificial disc configured to mimic the physiology of a natural functional spinal unit. . 16A-16C, 17A-17B, 18A-18C, and 19A-19C provide an illustration of an artificial disc configured to mimic the physiology of a natural functional spinal unit. . 16A-16C, 17A-17B, 18A-18C, and 19A-19C provide an illustration of an artificial disc configured to mimic the physiology of a natural functional spinal unit. . 16A-16C, 17A-17B, 18A-18C, and 19A-19C provide an illustration of an artificial disc configured to mimic the physiology of a natural functional spinal unit. . 16A-16C, 17A-17B, 18A-18C, and 19A-19C provide an illustration of an artificial disc configured to mimic the physiology of a natural functional spinal unit. . 16A-16C, 17A-17B, 18A-18C, and 19A-19C provide an illustration of an artificial disc configured to mimic the physiology of a natural functional spinal unit. . 16A-16C, 17A-17B, 18A-18C, and 19A-19C provide an illustration of an artificial disc configured to mimic the physiology of a natural functional spinal unit. . 20 and 21A-21B provide an illustration of a dual motion end plate that includes an internal motion end plate and an external motion end plate. 20 and 21A-21B provide an illustration of a dual motion end plate that includes an internal motion end plate and an external motion end plate. 20 and 21A-21B provide an illustration of a dual motion end plate that includes an internal motion end plate and an external motion end plate. 22A-22D provide illustrations of an artificial disc having a plurality of fixed fixation fins on the outer surface. 22A-22D provide illustrations of an artificial disc having a plurality of fixed fixation fins on the outer surface. 22A-22D provide illustrations of an artificial disc having a plurality of fixed fixation fins on the outer surface. 22A-22D provide illustrations of an artificial disc having a plurality of fixed fixation fins on the outer surface. 23A-23B provide an illustration of a partially cylindrical endplate and removable keel. 23A-23B provide an illustration of a partially cylindrical endplate and removable keel. Figures 24A-24B and 25A-25C provide illustrations of selectively deployable fixation screws and associated mechanisms. Figures 24A-24B and 25A-25C provide illustrations of selectively deployable fixation screws and associated mechanisms. Figures 24A-24B and 25A-25C provide illustrations of selectively deployable fixation screws and associated mechanisms. Figures 24A-24B and 25A-25C provide illustrations of selectively deployable fixation screws and associated mechanisms. Figures 24A-24B and 25A-25C provide illustrations of selectively deployable fixation screws and associated mechanisms. 26A-26C provide illustrations of other artificial disc fixation mechanisms. 26A-26C provide illustrations of other artificial disc fixation mechanisms. 26A-26C provide illustrations of other artificial disc fixation mechanisms. 27A-27C provide an illustration of an insertable keel structure. 27A-27C provide an illustration of an insertable keel structure. 27A-27C provide an illustration of an insertable keel structure. FIG. 28 provides an illustration of a fiber winding structure for joining the upper and lower motion endplates of an artificial disc. 29A-29B provide an illustration of a system that keeps the prosthetic disc thin during the implantation procedure. 29A-29B provide an illustration of a system that keeps the prosthetic disc thin during the implantation procedure. FIG. 30 provides an illustration of a core structure adapted for use with an artificial disc. 31A-31D provide an illustration of a spinal motion maintenance system. 31A-31D provide an illustration of a spinal motion maintenance system. 31A-31D provide an illustration of a spinal motion maintenance system. 31A-31D provide an illustration of a spinal motion maintenance system. 32A-32B provide an illustration of the intervertebral disc interlocking mechanism. 32A-32B provide an illustration of the intervertebral disc interlocking mechanism. 33A-33C provide an illustration of an artificial disc that is adapted to deploy in a generally X-shaped configuration. 33A-33C provide an illustration of an artificial disc that is adapted to deploy in a generally X-shaped configuration. 33A-33C provide an illustration of an artificial disc that is adapted to deploy in a generally X-shaped configuration. 34A-34B provide an illustration showing a surgical method for implanting an artificial disc. 34A-34B provide an illustration showing a surgical method for implanting an artificial disc. 35A-35D provide an illustration showing another surgical method for implanting an artificial disc. 35A-35D provide an illustration showing another surgical method for implanting an artificial disc. 35A-35D provide an illustration showing another surgical method for implanting an artificial disc. 35A-35D provide an illustration showing another surgical method for implanting an artificial disc. 36A-36I provide an illustration of a mechanism for joining a set of adjacent artificial discs. 36A-36I provide an illustration of a mechanism for joining a set of adjacent artificial discs. 36A-36I provide an illustration of a mechanism for joining a set of adjacent artificial discs. 36A-36I provide an illustration of a mechanism for joining a set of adjacent artificial discs. 36A-36I provide an illustration of a mechanism for joining a set of adjacent artificial discs. 36A-36I provide an illustration of a mechanism for joining a set of adjacent artificial discs. 36A-36I provide an illustration of a mechanism for joining a set of adjacent artificial discs. 36A-36I provide an illustration of a mechanism for joining a set of adjacent artificial discs. 36A-36I provide an illustration of a mechanism for joining a set of adjacent artificial discs. FIGS. 37A-37F provide illustrations showing other surgical methods for implanting an artificial disc. FIGS. 37A-37F provide illustrations showing other surgical methods for implanting an artificial disc. FIGS. 37A-37F provide illustrations showing other surgical methods for implanting an artificial disc. FIGS. 37A-37F provide illustrations showing other surgical methods for implanting an artificial disc. FIGS. 37A-37F provide illustrations showing other surgical methods for implanting an artificial disc. FIGS. 37A-37F provide illustrations showing other surgical methods for implanting an artificial disc. 38A-38F provide illustrations of some embodiments of a generally “J” shaped artificial disc. 38A-38F provide illustrations of some embodiments of a generally “J” shaped artificial disc. 38A-38F provide illustrations of some embodiments of a generally “J” shaped artificial disc. 38A-38F provide illustrations of some embodiments of a generally “J” shaped artificial disc. 38A-38F provide illustrations of some embodiments of a generally “J” shaped artificial disc. 38A-38F provide illustrations of some embodiments of a generally “J” shaped artificial disc. FIG. 39 provides an illustration of an encapsulated spring disc replacement system.

Claims (25)

An artificial disc,
The first end plate of exercise,
A second motion end plate coupled directly or indirectly to the first motion end plate in a substantially parallel relationship with the first motion end plate;
A core member disposed between the first and second end plates,
The first motion end plate includes an artificial disc that includes a fixing member that is selectively movable from a non-deployed state to a deployed state.   The artificial intervertebral disk according to claim 1, wherein the fixing member includes a keel slidably engageable with the first motion end plate.   The artificial intervertebral disc of claim 2, wherein the keel has a generally triangular cross-sectional shape, and the first endplate includes a slot having a generally trapezoidal cross-sectional shape for engaging the keel.   The artificial intervertebral disc according to claim 2, wherein the first motion end plate has a substantially curved cross-sectional shape.   The keel includes a base, a fixed fin extending outwardly from the outer surface of the base, and a coupling member on another surface of the base, the coupling member engaging the first end plate. The artificial intervertebral disc of claim 2, configured as described above.   The artificial disc of claim 5, wherein the base has a generally wedge shape to provide an anterior lordosis at the time of implantation.   The artificial intervertebral disk according to claim 1, wherein the fixing member in the expanded state extends outward from an outer surface of the first motion end plate.   The artificial disc according to claim 7, wherein the fixing member includes a retractable fixing fin.   The artificial intervertebral disc according to claim 8, further comprising a fixed fixing fin extending outward from an outer surface of the first motion end plate.   The prosthetic intervertebral disc of claim 9, wherein the fixed fixation fins are oriented generally perpendicular to the retractable fixation fins.   The artificial intervertebral disc according to claim 7, wherein the fixing member is moved from a non-deployed state to a deployed state by an expandable member positioned approximately between the first motion end plate and the second motion end plate. .   The artificial intervertebral disk according to claim 7, wherein the fixing member is moved from a non-deployed state to a deployed state by a screw mechanism positioned approximately between the first motion end plate and the second motion end plate. A first motion endplate including an inner member and an outer member, wherein the inner member and the outer member are rotatable relative to each other;
A second motion end plate coupled directly or indirectly to the first motion end plate in a substantially parallel relationship with the first motion end plate;
A core member disposed between the first and second end plates,
Rotating the inner member relative to the outer member causes the fixation member to extend outwardly from the first motion endplate.   The artificial disc of claim 13, wherein the fixation member includes a screw.   The artificial disc of claim 14, further comprising a slot formed in one of the inner member or the outer member, wherein the screw is configured to move within the slot.   The artificial disc of claim 15, wherein the slot is formed in the inner member of the first endplate.   The outer member of the first end plate is a screw adapted to engage the thread of the screw so as to facilitate extension of the screw outward from the first end plate 17. The artificial intervertebral disc of claim 16, comprising a hole.   The artificial disc of claim 17, further comprising a plurality of fixation members adapted to extend outwardly from the first endplate.   The artificial disc of claim 18, further comprising a plurality of fixation members adapted to extend outwardly from the second endplate. An artificial disc,
The first end plate of exercise,
A second motion end plate coupled directly or indirectly to the first motion end plate in a substantially parallel relationship with the first motion end plate;
A core member disposed between the first and second end plates,
The first endplate includes a central portion and a first side, the first side being in a first position substantially in the same plane as the central portion, and a plane substantially different from the central portion. An artificial disc having a second position at.   21. The artificial intervertebral disc according to claim 20, wherein the first motion end plate has a first hinge connecting the central portion and the first side portion.   The first end plate has a second side coupled to the central portion by a second hinge, the second side being substantially in the same plane as the central portion. And the second position in a plane substantially different from the central portion.   The second endplate includes a central portion and a first side, the first side being in a first position substantially in the same plane as the central portion, and substantially the central portion. 21. The artificial intervertebral disc of claim 20, having a second location in a different plane.   24. The artificial intervertebral disc of claim 23, further comprising a spring extending and coupled between the first side of each of the first endplate and the second endplate.   The first side of the first end plate and the second end plate each have a slot formed therein, each of the slots adapted to engage the spring. 25. The artificial intervertebral disc of claim 24.

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